GEOL. FOREN. FORHANDL. Bd 59. H. 1. 1937. 77
Minerals of the Varutriisk Pegmatite.
I. The Lithium - Manganese Phosphates.
By
PERCY QUENSEL.
(MS. received 10/? 1937.) The Varutrask pegmatite, lying between Boliden and the Baltic coast" about 20 km SE of the great Boliden mines, was first discovered in 1933, when dr O. BAECKSTROM, chief geologist of the Boliden Mining Co., drew my attention to a finegrained lilac lepidolite-fels which had been observed during some temporary blasting for quartz. Since then a good deal of work has been done, the Boliden Company reck oning with an eventual economic output of the lithium minerals. I have thereby had the opportunity to follow the workings during summer visits in 1934, 1935 and 1936. The abundance and beauty :." of many of the pegmatite minerals speedily drew attention to the i locality, and I hope in time to give a full description of the occurrence. -:.':.,...... The two last years have, however, yielded so rich an assortment of species • and raised problems of such singular interest, that the final publication has been retarded, awaiting further determinations on the abundant ·:.. :... material and final observations relating to the different stages of : mineralisation. I therefore propose here to give a preliminary account I., of one group of minerals only, namely the triphylite series and its
I.:.... decomposition products, which in Varutrask are represented in very P fine development. Especially the transition from fresh blue triphylite ! over an intermediate stage to the brilliantly purple heterosite is to ( be followed in exceptional detail, even well represented in single hand t specimens. 1 13pfnfe entering on this subject I wilL however, in form of a brief list, give an indication of the characteristic minerals of the locality, which up to date have been found and identified, affording an intimation of the general character of the pegmatitic mineralisation.
1 Further papers dealing with the minerals of the pegmatite, are planned to follow in this journal. Bd 59. H. j 78 PERCY QUENSEL. [Jan.--Febr. 1\137. is in thin s( Native elements: allemontite locally frequent y normal to Oxides: cassiterite abundant Y, occa~ Phospates: blue Mn-apatite frequent e > mination of amblygonite 2 modifications, one (montebrasite) abundant, one very scarce triphylite rather S0ar('E' ferri-sicklerite frequent heterosite frequent varulite (n. sp.) scarce alluoudite rather scarce Niobate-tantalates: columbite frequent Mn-tantalite scarce a mineral near stibio- tantalite scarce Silicates: cleavelandite abundant lepidolite abundant petalite abundant c spodumen locally abundant beryll frequent coloured turmalines abundant (black,green, red, blue) zeolites frequent i The pegmatite belongs to the so-called Skellefte granite, a fine- i grained outlyer of the great Revsund granite area of northern I Sweden, which is now considered to belong to the closing epoch of the .~ ancient svionian formation of the Swedish archaean. Fig 1. Specir The minerals treated in this paper are triphylite, ferri-sicklerite, In ring E, the heterosite, varulite and alluoudite.
So far th( The nor m a I t rip h y lit e s e r 1 e s. minations. The primary mineral of this series is in fresh state a deep sky-blue pOssessed di triphylite (fig. 1 A). In general one must however say that perfectly thin sertiOl fresh material is scarce. At commencing alteration the triphylite looses able to find. its blue colour and becomes wine yellow or clove-brown (fig. 1 Bj, ; recorded in types on the whole more common than the blue variety which as yet ~ In 3, few 1 has only been found quite locally, but there, at least in one place, been kind , relatively abundant. on the un The fresh blue triphylite OCCUI'S in. cua,r:::;egraiueJ deava1le llla:::;Ses· fOfseell and The luster is resinous, fracture uneven to subconchoidal. The usllill 6 --370J60. cleavages parallel (001) and (010) are well developed. The mineral :Bd 59. H. 1.] MI~ERALS OF THE VAIWTRASK PEGMATITE. 79 rJ an.~-Febl'. 1\)37. loeally frequent " in thin seutioll eolourless. The axial plane is parallel (001) with :~ normal to (010). The character is optically +, dispersion very strong, abundant ~ frf'qupnt /' y, occasioning. anomalous indigo-blue interference colours. Dcter - l'llutjnn of thp aXIal ang]p ,gavp: 2V,." = :2OC). ;2 lIludiIiGations, III ' ,_.,.. abundant, ont> scarce rather scarce ~requent :requent lcarce 'ather scarce requent carce carce .bundant bundant bundant )cally abundant ~equent bundant (black,green, ' red, blue) requent lefte granite, a fine te area of northern I
: closing epoch of the I MARGIT ROSENBERG• .ean. r Fig. 1. Specimen of blue triphylite (A) with alteration ring of ferri-sicklerite (C). rlite, ferri-sicklerite, In ring B, the blue triphylite has turned yellow, due to beginning alteration. Anal. of A and B page 81, of C p. 84. er i e s. So far the optical properties seemed to coincide with previous deter minations. An instance indicating that the triphylite of Varutrask tate a deep sky-blue possessed divergent qualities, was the observation of twinning in one ~r say that perfectly thin section of blue triphylite (fig. 1 A). As far as I have been the triphylite loose"s able to find, twins have not before been observed in triphylite, though )ve-brown (fig:. 1 B). fpf'orded in thA nAar]y related hery]]onite. The twinning is repeated variety which as yet ' in a few broad polysynthetic lamellae. Dr VON ECKERMANN has least in one place, been kind enough to corroborate the twinning law by measurements on the universal stage. The result is in several respects so un .ed cleavable masses. forseen and the conclusions which may be drawn, imply so far- tlchoidal. The usual 6-370060. G. F. F. 1937. :loped. The mineral 80 PERCY QUENSEL. [Jan.-Febr. 1937. Bd 59. H. 1. reaching consequences, that I cite VON ECKERlVIANNS observations the diverger: in extenso: ~ignificant, i »At the request of Pro£. QUENSEL, I have undertaken the in with Lane pI vestigation of an apparently twinned crystal, observed in a thin to this quest section of triphylite-rock from Varutrask. In section the mineral reckon with is colourless, the refringence and birefrigence agreeing with those Principally of the triphylite. As no mentioning of twinned triphylite is found and thereby III the literature, the question arose whether another mineral - In,hiophili1 or a haphazard growth of separate trlphylite crystals were present. by Lir R. BLl The investigation was carried out on the universal stage in 1\1nO and 25. sodium light. The crystal-section consisted of two somewhat in question c, narrower marginal and one broad central lamellae, the joints presume a cc being straight and strictly parallel; not coinciding with any part analyses plac ings of the mineral. The optical orientation of the marginal la phylite grouI mellae was found to be identical. philite group The two systems of lamellae constitute undoubtedly a true speCIes may polysynthetic twinning, in the present case cut almost at right in Mn. angles to the twinning-plane and slightly oblique to the acute As triphyli bissectrices of both twins. The optic plane makes an angle of able to obtai 4° with the trace of the twinning-plane, and the latter is not quite of the Bolidl perpendicular to the a,B-plane; 87.5° being the average of several THEL~1A BER determinations. The axial angles of both twins were measured holm. The t, at 2VNa = 26° ± 0.5°; the refringence of triphylite, as determined A. and B in fi by QUENSEL, being used when calculating the corrections of the brown triphy readings. Evidently, the mineral is not Ol'thorhombic. In order to com Unsoh,ble • H 0-105° pare it with the un-twinned, presupposedly orthorhombic, tri 2 phylite of the same sample, another section was prepared where R2°-i-105" Fe20 3 the mineral was cut almost parallel to the a,B-plane, exhibiting !1203 nicely developed cleavages parallel to 001. The extinction-angle FeO a: (001) was found to be 4° and the axial angle was determined at MnO .; CaO 2V = 26° ± 0.5°. Na llg0 These values correspond exactly with those 01 the twinned 11 20
crystal, assuming the twinning-plane to be (001). All other optic :Ka 20 .
characteristics being equal, there seems to be small doubt ot the K 20 . two minerals being identical. P/\ . The results of my investigation, consequently, seriously question the orthorhombic character of the triphylite of Varutrask indicat Sp. gr..... ing, as they do, a lower pseudo-orthorhombic symmetry. They 1. Fresh bI ne ~. Wine-yellow also call for a revisal of earlier measurements of triphylite crystals,) .3. Triphylite I must for the present restrict myself to i1raw a,tJ,pntion to thf>se ~. TriphvIite: J. TriphYlite. facts. To definitely proof the symmetry of Ll'iphyliLe, espeeially as rJ an.--Febr. 1937. Bd 59. H. 1.] MINERALS OF THE VARUTRASK PEGMATITE. 81 gRMANNS observatioIls he divergence from orthorhombic symmetry in any case is in \.nificant, it will be necessary to corroborate the new observations ~o vc undertaken the in " .rith Lane photographs. I happ opportunity may be offered to return d. Oh8P"fwd in a thin_ ~ ;0 this question in a future puLlication. Till then we must, however, [n section the mineral J eckon with the probability that there exists a clino-triphylite. ~e agreeing with those f r Principally in order to determine the proportions between Fe and Mn led triphylite is found I snd thereby localize the triphylite in the isomorphous series triphylite ther another mineral ~_ Iithiophilite a partial analysis was already at an early stage made crystals were present, by dr R. BI.. IX of the State Natural History Museum, giving 19.53 % le universal stage in linO and 25.79 % FeO, all Fe reckoned as FAO. The mineral species ~d of two somewhat lU question can therefore be classed as triphylite. For even if one can seri~s ~nd lamellae, the joints presume a continuous between Li!eP04 LiMnP04 , existing ciding with any part I analyses place known speCies rather deCIdedly III two groups, the tri 1 of the marginal la- ~ ph!~ite group ~ith MnO<20 % and ?5-40 % FeO and the lit~~o I ph1hte group WIth FeO<20 % and 2D-·40 % MnO. The Varutrask undoubtedly a true species may therefore be said to represent a triphylite relatively rich cut almost at right iu Mn. >blique to the acute As triphylite is a new mineral for Sweden, it was considered desir ~ makes an angle of able to obtain more complete analytical data. Through the courtesy ihe latter is not quite of the Boliden Mining Co. three analyses have been made by miss le average of several TUELMA BERGGREN of the Companys Research Laboratories in Stock wins were measured holm. The two first refer to the two modifications represented by ring hylite, as determined Aand B in fig. 1. The third represents a somewhat oxidized yellowish le corrections of the hrown triphylite, found at an earlier stage of the investigation. 1. 2. 3. 4. 5. lC. In order to COIn Unsaluble • 1.24 5.80 0.20 y orthorhombic, tri jf~O-105' 0.29 0.13 0.05 was prepared where IJIIO +105° 0.31 0.36 0.64 1.47 0.42 Fe 0 • 0.00 0.33 6.30 a,B-plane, exhibiting 2 3 A120 3 0.00 0.00 0.00 The extinction-angle FeO 24.33 22.85 18.21 26.23 26,40 le was determined at '.ll1l0 . 18.95 18.16 20.16 18.21 17.84 UaO . 1.82 1.84 1.36 0.94 0.24 1 .ose of the twinned jl!gO . trace 0.11 0.00 0.59 0,47 ~i,O . 8.52 7.92 6.06 9.36 9.36 01). All other optic 'ia2 0 . 0.16 0.58 2.28 0.12 0.35 small doubt of the {O 0.00 0.00 0.00 0.32 " 2 ?20fi . 44.10 42.23 44.47 44.03 44.713 ~~----- T, seriously question 99.72 100.30 99.73 10070 99.81 f Varutdisk indicat 'p. gr . 3.423 3.384 3.521 3.52 3.534 lC symmetry. They Fresh blue triphylite, Varutrask CA in fig. 1). I Wine-yellow triphylite (B in fig. 1). triphylite crystals.}) J, Triphylite, somewhat oxidized attention to these Triphylite, Grafton, :New Hampshire, D.S.A. lylite, especially as i. Triphylite, Norwich, Mass. 82 PERCY QUENSEL. [Jan.-Febr. 1937. Bd 59. H. 1. Analyses 1 and 2 come very near the old analyses of PENFIELD of triphylite from Grafton and Norwich, which are given above for efJlll-: chemical invc parison (N:o 4 and 5). . Mn as "MnO aJ Analysis 1 indicates a very pure triphylite. Recalculated to 100 %' tion was draw the molecular ratios are 946: 317 or nearly exactly 3: 1. Analysis 2 of oxidation' represents an intermediate zone between the blue triphylite and an fresh triphyli1 alteration product, ferri-sicklerite, described below. The triphylite of qualities and this zone has changed colour to wine-yellow, but shows hardly any! to represent:
other change than an insignificant oxidation of 0.33 %Fe20 a• Analysis 3: intermixed wi shows on the other hand more advanced oxidation, a fourth part of the! idation from 1
iron being present as Fe20 a• This analysis is also of interest because of [ are chemicall,
the relatively high content of Na20. Of former analyses of triphylite I and Fe occur
none exceeds 0.50 % Na20. It lies near at hand to reckon with an i, intermixture of a third component in the triphylite -lithiophilite series, ! namely the natrophilite molecule. Already BRUSH and DANA have. shown that natrophilite is intimately associated with lithiophilite in i Brancheville. On the other hand one might reckon with the possibility The new m
of a substitution of Na2 0 for Li20 during the oxidation, analogous to in colour, the the formation of p-spodumen, described by BRUSH and DANA from purple streak Brancheville. I will here restrict myself to drawing attention to the if dipped in a fact, as opportunity will be given further on to return to the question, tion, a brOWl where a third explanation is discussed (p. 95). species, whic} of Mn, there Under the We may now proceed to the more advanced stages of alteration and almost u of the triphylite from Varutrask. A mineral belonging to this category ing makes 0] at an early date drew our attention by the brilliant purple colour vage of the ( of its streak. It was easy to define this mineral as belonging to thL llldices of re] heterosite - purpurite series. When I, therefore, in 1936 through the Two compI mining geologist of the Boliden Co. dr O. ODMAN received a fine spec the outer rin imen of blue triphylite, surrounded by a darkbrown ring, (A and C the farm Lov in fig. 1), I naturally presumed that I had in my hand the transition· lerite, a neal from triphylite to heterosite, which mineral is always black to dark SCHAI,LER. ) brown in field specimens due to a thin coating of a hydrogenous phos-' results, indic: phate of Fe and Mn. It soon, however, became evident that the alteration I only with a ] products of triphylite were of a more complex nature and that at I Both anab least one definite intermediate stage of oxidation was represented at the formula:" Varutdi.sk. Already in the summer of 19:35 dr O. BAECKSTROM had in an out lying pegmatite dike near the small farm of Lovlunden, about three The small an km NE of Varutrask, found specimens of a mineral, which could :not on.ly suffice lw iJentified with any other mineral of the district. A preliminary FeO, is n.earl [Jan.-Febl'. 193~ I, :Bd 59. H. 1.] MINERALS OF THE VARUTRASK PEGMATITE. 83 analyses of PENFIELn I . b 0 HA c0!l:l. hewical investigation showed it to be a Fe-Mn phosphate with all glven a ove for c . \tIn as l\1nO and the whole Fe content as Fe2 0 3 • Later on, as my atten- Recalculated to 100 0 ~ion was (lrawn to the case, it '.vas found that thi" IlltermeJitlte product ~xactly 3: 1. Analysis I~ of oxidation was by no means uncommon. The dark ring round the blue triphylite and a" fresh triphylite (0 in fig. 1) was found to possess the same chemical below. The triphylite o~ qualities and where triphylite is still found unaltered, this species seems , but shows hardly an;' to represent a common and more initial stage of alteration, alone or
).33 %Fe20 3 • Analysis 3\ intermixed with the more fully oxidized heterosite. The stages of ox-· tion, a fourth part of thf I idation from triphylite over the new intermediate product to heterosite .Iso of interest because of I are chemically characterized by practically the whole content of Mn Ler analyses of triphylite and Fe occurring as follows: Land to reckon with an triphylite MnO ite - lithiophilite series, t inteI'm. stage MnO 3RUSH and DANA have I heterosite Mn 20 3 ;ed with lithiophilite in :;kon with the possibility The new mineral, representing the intermediate stage, is dark brown oxidation, analogous to in colour, the streak and powder brown to brownish red. The brilliant 3RUSH and DANA from purple streak of the heterosite-purpurite series is quite lacking. Also 'awing attention to the Iif dipped in acid, to remove the usual thin black coating of later altera- return to the question, rion, a brown colour appears, not the purple of the higher oxidized ). ' species, which naturally is dependant on the higher state of oxidation lof Mn, there at hand. r Under the microscope the mineral is of a deep reddish brown colour ed ~tages of. alteration! and almost unpleochroitic. Subtr:anslucent to opaque, the deep colour on?I~lg to thIS category i.ng makes optical determinations difficult and unreliable. The clea bnllmnt pur~le colom i vage of the original triphylite is readily distinguishable. The medium ral ~s belongmg to thtjmdices of refraction is well over 1. 78. re, III 1~36 thr~ugh thf, Two complete analyses have been made by miss BERGGREN. N:o 1 is AN recen~ed a fme spec- the outer ring surrounding the fresh triphylite, (fig. 1 C), no. 2 is from [brown rmg, (A and Cthe farm Lovlunden where the mineral was first found. No. 3 is sick ay hand the transitionlerite, a nearly related phosphate from Pala, Cal., first described by always black to dark-.scHALLER. As seen, the two analyses from Varutrask give very close )f a hydrogenous ph.oS-iresults, indicating that we have to deal with a definite mineral and not dent that the alteratlOnilnly with a link in a progressing series of alteration products. x nature and that at" Both analyses of the Varutrask material correspond fairly well to on was represented atthe formula:
STROM had in an out
)vlunden, about t.hreerhe small amount of H 2 0 has, however, then been left out, as the bases
Ieral, which could notonly suffice to bind P20so The ratios bases to P 2 0 5, all Fe counted as strict. A prelimillary!B'eO, is nearly exactly 3 : 1 (952 : 315). J1 84 PERCY QUENSEL. [J an.-Febl'. lGB7. ! Bd 59. H. \
1 a. 1. further on. mol. prop. which SCE Unsoluble . 1.66 Evidently j HzO -105° . 0.51 The sickl HzO +105. 0.51 near the Va FeZ0 3 27.20 0.170
Mn Z0 3 0.00 from analy Alz03 0.00 It is diffi FeU. 0.59 0.008 Pala sickle ~InO 19.13 0.270 lithiophilit( OaO . 1.36 0.024 MgO. 0.11 0.003 twccn Fe aJ LizO. 3.72 0124 relations bl NazO 0.81 0.013 or lithiopb KzO. 0.00 analysis p' pzO•. 44.80 0.315 tions RO : 100.40 brief descr Sp gr. 3.391 as to the r( properties The amount of FezOa is naturally dependant on the accessible amount much the ~ of Fe in the original triphylite and the proportions RO : RzOa can there for not be expected to present any strict molecular proportions. sicklerite In discussing the analyses, the following points maybe worth notice, ating the 1 comparison being made between the fresh triphylite and the outer The two ring of alteration in the same hand specimen. so alike th: phyhte an It is obvious that Mn, Fe and PZ0 5 have practically remained con stant, the changes are: MnO from 18.95 to 19.13, FeO from 24.33 to ferri-sickle of Mn has] 25.08, (counting all Fe as FeO) and P 0 from 44.] 0 to 44.80. The Z 5 gressing ait only evident change which has taken place, refers to the almost complete of the hetel oxidation of FeG and to the leaching of Li 0 which has been reduced 2 We may from 8.52 % to 3.72 %, or to less than half the original content. stage of ox The amount of leaching of the alkalies has to all evidence been regulated in proportion to the oxidation of FeO. The molecular ratios between SCHALLER': serie8 lithi bases and P205 has remAined unchanged, 9,16 : 317 in triphylite, %2: signified a: 315 in the alteration product. of the pr; As far as I have been able to find, no mineral in all respects corres indicates i' ponding to the composition given above, has been described, ttough I several species, referred to as alteration products of triphyJite or lithio philite with Mn as MnO and Fe as Fe20a are known. I refer to the old tripbylite . species alluoudite of DAMOUR (1848) and to salmonsite and sicklerite ferri-sicklerit heterosite . of SCHALLER (1912). Of these, however, none strictly coincide with the chemical relations cited above. Rather nrar comes alluoudite, but the content of Na 2 0 substituting Li 20 places this mineral in a separate t lithiopbiIite daB;:). A mineral ulosely resembling alluoudlte is reprPRPntpct at Varu' skklerite . trask and I will return to the gucDtion of itD position and relations purpurite [Jan.-Fob". 1931f]ld 59. H. 1.] MINERALS OF THE VARUTRASK PEGMATITE. 85
further on. Salmonsite is strongly hydrated with 15.30 % H 20, for op. 2. 3... which SCHALLER gives the formula 9MnO Fe20 3 4PZ0 5 14 H 20. 2.42 I 4.18 ~ Evidently it is not our mineral. 0.79 ~ 0.44 I 1'he slcklerite from Pala, on the other hand, in many respects comes 29.08 1;:;~ i Ilear the Var~tra~k alteration produc~. The formula given by SC~ALLER 2.1Q; frolll analysIs 3 III the table above IS : 6MnO Fe203 4P205 3(Ll, RhO. 0.00 _ ! It is difficult to say, how near these two minerals are related. The 0.22, I' Pala sicklerite, by SCHALLER considered as an alteration product of 15.20 33.6Q lithiophilite, is essentially poorer in iron. The relative proportions be- 1.88 U.20 i 1.70 _ i tween Fe and Mn are, however, in this case of little consequence, these 3.26 3.8Q I relations being dependant on the allotment in the primary triphylite 0.88 _ t or lithiophilite. SCHALLERS sicklerite shows, according to the only 0.00 - I analysis published, a slightly diverging composition, the propor- _44._~4 ~ I tions RO :P 2 0 5 being 9: 4 instead of 9 : 3 in our mineral. The very 100.51 99.95 I brief description of sicklerite does not allow a positive conclusion 3.271 I as to the reliability of the analytical data. As, however, known optical n the accessible amount I properties agree and the paragenesis of both minerals is to all evidence much the same, I propose to name the mineral from Varutrask ferri- ns RO : R 20 3 can there- I llecular proportions. sicklerite, indicating a relationship to the Pala sicklerite but accentu- ts may be worth notice, ating the higher content of iron. iphylite and the outer The two analyses of ferri-sicklerite, from two different localities, are so alike that one cannot doubt a definite s-pecies. The oxidation of tri wtically remained con- I phylite and lithiophilite to all evidence does not proceed continuously, ferri-sicklerite marking a stage where all Fe is oxidized but the oxidation 13, FeO from 24.33 to I of Mn has not yet set in. This would denote a halting-point in the pro II 44.10 to 44.80. The I to the almost complete gressing alteration, the next stage would be represented by the minerals of the heterosite - purpurite series, when also all Mn has been oxidized. 1hich has been reduced f the original content. We may therefore define ferri-sicklerite as representing a definite evidence been regulated stage of oxidation in a series triphylite - ferri-sicklerite - heterosite. llecular ratios between SCHALLER'S sicklerite would probably represent the same place in the 317 in triphylite, 952: series lithiophilite - sicklerite - purpurite and might therefore be signified as Mn-sicklerite. The following table, with the percentages LI in all respects corres of the principle constituents, taken from representative analyses, been described, though indicates such a succession: ; of triphylite or lithio 1. Triphylite series. lwn. I refer to the old triphylite .. Li/) 8.f>2 MuO 18.95 FeO 24.33 P205 44.10
monsite and siekIerite ferri-"jC'klerite " 19.10 F02 0 3 27.20 44.60 :ietly coincide with the heterosite .. 0.46 27.44 41.93 comes alluoudite, but n. Lithiophilite series. s mineral in a separate lithiopbilite Li 2 0 8.50 MnO 3b.fl8 FeO 8.60 P 20 a 44.40
is represented at Varu- sicklerite . 3.80 » 33.60 Fe30 3 11.26 43.10
position and relations purpurite . Mn Z0 3 29.25 15.19 47.30 86 PERCY QUENSEL. [Jan.-Febr. 1937. Bd 59. H. 1.
It is of interest to note, how nearly equivalent, the reduction of Attention' Li2 0 is in both the two intermediate stages, from an original content of the brillian of about 8.5 % in triphylite and lithiophilite to 3.72 in ferri-sicklerite The mineral and 3.80 in the Pala sicklerite. Mn and Fe also remain in their original this was soon proportions and percentage. The only change is the intermittent oxi which, penetr, dation of Fe in the first instance and of Mn in the second and the colour of the : leaching of the alkalies. with cold, dil An extra indication that ferri-sicklerite represents a definite miner Under the al species, is given by an X-ray powder photograph which pro£. WEST in yellow-gra GREN has kindly taken (fig. 2), shortly discussed further on in reference triphylite are also to heterosite (p. 89). mterwoven w We may now proceed to the next stage of oxidation, represented cleavages. Tl by the mineral heterosite. will be descri Concerning tbe name of this phosphate, different opinions have been To control asserted. LACROIX1 has referred SCHALLER'S new mineral purpurite2 oxidation, a F to the older heterosite of ALLuouD (1826), and is of the meaning that result: purpurite >)ll'est qu'une heterosite plus manganifere que celle du Li mousin». In this case the name heterosite has naturally priority. All Mn anc It is, however, evident that there exists a series heterosite -- purpurite of Mn 0 and: with the same difference in proportions between Mn and Fe as in 2 a to the amoun the series triphylite - lithiophilite. It seems therefore appropriate to retain both names, as SCHALLER also proposes in a later publication,3 representing the same chemical distinctions as are maintained between triphylite and lithiophilite. This is all the more wellgrounded, inas much as the material from Varutriisk clearly indicates that no change Already this ( of any importance concerning the Mn - Fe proportions has taken these element: place during the process of alteration. In agreement with SCHALLEH As publishe( the mineral here in question is named heterosite, indicating the altera are scarce anc tion and full oxidation product of triphylite. executed on s The heterof:lite occurs at Varutrask in larger or smaller nests and material :from nodules, widely disperf:led through different parts of the pegmatite. it was desirab One of the largest nodules measured over 4 dm in length and 2 dm in ready complir; bredth. In consequence of the strong tendency to alteration which all two complete species of the triphylite -~-lithiophilite series show, the original triphy Varutrask, het lite is seldom preserved in larger quantities in the heterosite nodules. SW ~Hrica on] Under the microscope, however, rests of triphylite are often to be ob kindly put at 1 served. The transition is in most cases singulary sharp, again indicating the only two I the absence of gradual oxidation. Ferri-sicklerite is of course often noted and Kings Mt, as an intermediate product, but between the three stages a marked Finally an ana hiatus is pronounced. original locali
1 .!\1in. de .FmULt, \'UJUl' 'i, p. 40J. avatlabJe ana!' 2 Am. Journal of Science, XX, 190f:>, p. Ho. 1 Cfr. Brush aI a Bull. U. S. Geol. 8urvey, 490, 1911, p. 72. [Jan.-Febr. 1937. :Bd 59. H. 1.] MINERALS OF THE VAIWTRASK PEGMATITE. 87 lent, the reduction of 1 Attention was early drawn to the heterosite at Varutrask because m an original content ~ f the brilliant purple streak, produced by scratching the black fmrfacp. 3.72 in fcrri-sicklerite : ~he mineral in fielrl RpeC'lmenf< always shows a dull black coluUl', but emain in their original this was soon found to depend on a thin coating of another phosphate, ~ the intermittent o~i. which, penetrating every cleavage and crack, completely obscures the true in the second and the ralonr of the mineral. The black fragments, when treated for a moment ;vith cold, diluted HCI, show up in radiant purple colouring.! ,ents a definite miner. Under the microscope the heterosite shows an intense pleochroism
Ih which prof. WEST I in yellow-gray, red and deep purple. The cleavages of the original turther on in reference tri;hylite are generally well retained. The mineral is often intimately . interwoven with narrow streaks of a yellow phosphate following the Kidation, represented \, cleavages. This is possibly identical with the mineral alluoudite, which \. will be described further on. lt opinions have been t To control the relative proportions of Mn and Fe and the state of w mineral purpurite2 I oxidation, a partial analysis was made by dr BLIX giving the following of the meaning that result: fere que celle du Li Mn20 a 21. 14- Fe20 S 28.30 s naturally priority. All Mn and Fe were present as trivalent oxides. The proportions ~terosite - purpurite " Iof Mn20 S and Fe20 S, reduced to MnO and FeO, nearly exactly correspond 1 Mn and Fe as in to the amount and proportions in the analysed triphylite: herefore appropriate I a later publication,s I, triphylite heterosite maintained between , FeO 24.33 25.46 wellgrounded, inas- I MnO 18.95 19.00 ates that no change Already this early analysis indicated that no exchange or removal of portions has taken these elements had accompanied the alteration. ent with SCHALLER As published analyses of the heterosite - purpurite group of minerals dicating the altera- are scarce and the U. S. A material, treated by SCHALLER, has been executed on small quantities and partly impure material, whereas the r smaller nests and material from Varutriisk ,vas both abundant and exceptionally pure, : of the pegmatite. it was desirable to get a new complete analysis made. Through the length and 2 dm in lready compliance of the Boliden Co., Miss BERGGREN has executed alteration which all j'jWO complete analyses on singularly pure material, the one of the the original triphy Varutrask, heterosite, the other of so-called purpurite from Erongo in heterosite nodules. lsw Africa on material, which prof. P. RAMDOHR of the Berlin University are often to be ob kindly put at my disposal. The analyses are given below; for comparison rp, again indicating the only t,H) uther analyses of later years, from Hill City, S. Dakota f course often noted and Kings Mt, N. Carolina, both published by SCHALLER, are appended. ~ stages a marked 'Finally an analysis by PISANI, citied by LACROIX, on material from the original locality of Chanteloube, France, is given, concluding the available analytical data of any importance.
. --~-----_._--_.._-- 1 Cfr. Brush and Dana. Am. Journ. of Science 1879, XVTT, p. 367, 88 PERCY QUENSEL. [Jan.~Fehl'. 1 :l~) 7. Bd 59. H.
1. 2. 3. 4. D. Both the n Unsoluble 0.30 0.19 0.52 proportion . H 0 _ 105° . 1.67 1.08 1.95 2 deducted f( H 0 + 105° . 1.65 2.33 4.82 3.31 7.62 2 2 : 2 : 1 for Fe20 3 2i.44 33.42 38.36 15.89 24.60 be~ Mn 20 3 20.42 15.14 12.18 29.25 29.35 CaO has MnO 3.60 l.53 is given off (:aO 1.70 1.16 1.37 1.18 conclusion, MgO 0.17 0.00 In my calcl Li 0 0.46 0.83 trace 2 SCHALLER h Na20. 1.12 0.7:.' 0.84 ing the stat( K 20 0.00 0.00 P205 . 41.93 43.79 43.45 47.30 41.60 rather poin
100.46 100.00 100.27 100.54 10B.17 F20 S H 20. 0.3 1. Heterosite, Varutrask. anal. Thelma Berggren 1936 Sp. gr. 3..109. 2. Heterosite, Erongo, SW Africa. anal. 'rh. Berggren 1936 Bp. gr. 3.398 I 3. Heterosite, Hill City, S. Dakota. anal. W. Schaller 1911. 4. Purpurite, Kings Mt. N. Carolina. > 5. Original >Heterosite>, Chanteloube, France. anal. Pisani 1910.
Both the new analyses show almost identical ratios for R 20 3 : P2 0S
The heterosite from Varutrask gives R 2 0 3 : P 20 S 301 : 295 from Erongo 305 : 308 Clearly, the small amount of RO bases are bound in other ways than as phosphate. Fig. 2. X-Ra To all evidence the oxides in the heterosite -- purpurite series replace each other in as varied proportions as in the triphylite --lithiophilite series. From 6 analyses, (the 5 tabled above and one incomplete from It may Brancheville, Conn.) I have calculated the following allotment: Korwich, M near the n
FC 20 3 P 20 S ])lu 20 3 P 20 S near the tr: 1. Hill City, S. Dakota 76 24 from Non\ 2. Erongo, SW Africa. 68 32 analogous 1 3. Varutrask ..... 57 43 phylite seri 4. Brancheville, Connecticut. 53 47 BesideR t 5. Chantcloube ..... 45 55 6. Kings Mt., N. Carolina .. 35 6h series have Bavarill,3 iJ Following SCHALLERS proposal regarding nomenclature, the 4 first are lithiophilitE to be classed as heterosite, the two last as purpurite. Professor The new analyses from Varutrask and SW Africa do not confirIIl some X-ra) Tite-~heter( SCHALLERS formula respecting the content of H 20. Miss BERGGREN, however, has drawn my attention to the fact that the mineral is highly , Am.•lOUl hygroscopic after pulverisation so that it IS difficult to form conclusive ? 1lAKINEN evidence on older analyses, made 011 insufficient or defective material. 'i LAU3MA:t [Jan.- Fobr. MINERALS OF THE VARu'rltAsK PEGMATITE. 89 4. O. Both the new analyses show a content of H 2 0 nearer 1/2 than 1 in 0.52 proportion.to P20S' In fact if the ratio~ for the combined alkalies ~rc 1.95 - I dedllded tor K() H\. hot.h analyses g1VP almost, pXHdly Hp rat,lOR 3.31 7.62 ') • '7, : 1 for R 0 : P 0 : H 0. But then the small content of MnO and 15.89 24.60 ... - 2 a 2 S 2 29.25 29.35 I CaO has been left out. SCHALLER also emphasises that the water which is given off at 105°, »goes very readily and at one time», and draws the 1.48 cOl~clusion, that it most probably is present as water of crystallization.
trace In my calculation I have combined H 20 above and below 105°, as also 0.84 SCHALLER has done. Though} can draw no conclusive evidence respect
ing the state in which H 20 partakes in the constitution, the new analyses 41.60 the~formulalR20a'P20s __4_7_.3_0 rather point to 1/2HO than to SCHALLERS R 2 0 a 100.54 103:17 P20 S H 2 0.
~r. 3A09. Sp. gr. 3.398
Triphylite 1910. Ferri sicklerite ios for R20 a : P205 1 : 295 5: 308 Heterosite )ther ways than as Fig. 2. X-Ray Photographs of Triphylite, Ferri-sicklerite and Heterosite obtained lrite series replace with Cr·K Radiation. ite --- lithiophilite \ incomplete from It may be of interest to note an old analysis of heterosite from ~ allotment: Norwich, Mass. by MALLET,! which in respect to content of water stands Hear the new analyses. It will be recollected tha,t a triphylite very
Mn 20 3 P 2 0 5 near the triphylite from Varutrask in chemical composition, also came 24 horn Norwich. The conditions at Norwich seem to have been very 32 analogous with Varutrask respecting formation of minerals of the tri 43 phylite series and their decomposition products. 47 55 Besides the localities, citied above, minerals of the heterosite-purpurite 65 series have been described from Tammela in Finland2 and HUhnerkobl, Bavaria,a in both cases associated with minerals of the triphylite . e, the 4 first are lithiophilite series. Professor WESTGREN haR at my rpf]llp,"it hppn kino pnOllgh to takp do not confirm some X -ray powder photographs of the series triphylite - ferri-sickle Miss BERGGREN, rite-~heterosite. The photographs. here reproduced (fig. 2), show mineral is highly , form conclusive 1 Am. .J ourn. of Science 1854, XVIn p. 33. 2 MAKINEN, Bull. Com. Geol. de Finland, 35, p. 95. ~fective material. " LAUBMANN & STEINMETZ, Zeitschr. f. Kryst. 55, p. 562, 574. Bd 59. H. 90 PERCY QUENSEL. [Jan.-Febr. 1937. was remov marked dissimilarities between the three minerals. Awaiting opportun with a knij ity for further structural analyses, I here restrict myself to cite the The result following lines communicated by WESTGREN: »From X -ray powder photographs of mineral specimens, specified as triphylite, ferri-sicklerite and heterosite, may be concluded that each of them mainly represents a special phase. The strongest interferences of ferri-sieklerite sho\\" up a,s faint lines in the X-ray patterns of heterosite indil;aLing that the latter specimen contains somewhat of the same phase as ferri sicklerite.» I will now return to the question of the black coating, which, as The figu already mentioned, always is found on field specimens of heterosite anticipate< or purpurite, masking the true colour of the minerals. This coating alteration has probably been held for Mn02 according to descriptions from several trask at : 1 localities. LACROIX for example speaks of psilomelan as a secondary penetratin product of alteration of triphylite occurring parallel with the transfor hydrated mation to heterosite or hureaulite, and l\fAKINEN2 has presumed the same interpretation for evidently quite the same phenomena regarding the heterosite from Tammela. He says that »sogar die feinsten Spriinge sind von einer schwarzen, halbmetallisch glanzenden Substanz erfiillt, die sehr dentlieh auf Mn reagiert und wahrscheinlich aus Pyrolusit We now besteht.» of the tTi A qualitative proof showed, however, that at Varutrask the black Already covering was a phosphate, containing Fe20 3 , Mn20 3 and H20. I then wa.s found noted references by BRUSH and DANA3 and by GRATON and SCHALLER,4 series. Tt evidently referring to the same phenomena. Whereas BRUSH and DANA 2--3 cm j refer to a decomposition product of lithiophilite, GRATON and SCHALLER On weatht refer to a direct alteration product of purpurite from N. Carolina. often appt They say »the purple mineral is always covered or surrounded by a On cleav~ greater or less thickness of a black or brownish-black material of pitchy turns yell luster and uneven or sub-conchoidal fracture. This material was found treated in to contain iron, manganese, phosphoric acid and water.» The authors tinge. expressed hope that sufficient material would soon be forthcoming Under' for an analysis, but, as far as I can find, nothing has been published since pure. Tra 1905" except in U. S. Geol. Survey, Hull. 490 p. 7:1, where SCHAJXrm to heteros mentions a coating of black, secondary material on lithiophilite from or globul: N. Carolina, also occurring as a narrow zone between lithiophilite and It was purpurite. another S] Miss BERGGREN has been kind enough to make some quantitativp ProL AlVII tests of the black coating on the hetcrosite of Varutrask. The coating allowed a
1 Min. de France IV p. 363, 470. Dept., elr' 2 Bull. Com. Gcol. ut; FLulallJ, 3J, 11. DJ. 3 Am. Journ. of Science, 1879, XVII, p. 367. 1 Am. Jouru. of Science, 1905, XX, p. 148. lld 59. H. 1.] MINERALS OF 'HR VARU'RASK PEGMA'!'E. 91 [Jan.-Febr. 1937. 'f, , was removed by scraping the outermost layer of the black heterosite Awaiting Oppoltun_ with a knife. In this way 0.0466 gr was obtained from 21 gr heterosite. ct myself to cite the f 11 The result wal:l as 0 ows: 'rom X-ray powder 01 ;,0 1ylite, ferri-sicklerite H 0 14.1 m mainly repreSellts 2 Fc 0 23.2 ferri-sicklerite show 2 a Mn 0 29.1 )site indicating that 2 a CaO trace 9.me phase as ferri- P20 5 31.2 coating, which, as The figures are only approximate. As already BRUSH and DANA have imens of heterosite anticipated for Brancheville material, no definite composition of these erals. This coatinO' ,.., alteration products is to be expected. The observations from Varu iptions from several trask at any rate signify that the black coating on the heterosite, \lan as a secondary penetrating the mineral by every cleavage and crevace, is a strongly 1 with the transfor- hydrated Fe-Mu phosphate. has presumed the enomena regarding ie feinsten Spriinge The sod i u m-a c c e n tu ate d s u b-s er i e s. n Substanz erfiillt, lich aus Pyrolusit We now pass over to what I think may be termed a parallel sub-series of the triphylite - lithiophilite group. arutrask the black Already at an early stage of the investigation a MnO-Fe20 a phosphate and H 2 0. I then was found, which did not correspond with any species of the former )N and SCHALLER,4 series. The mineral occurs rather scarcely in well defined nodules of BRUSH and DANA 2-3 cm in diameter. At Lovlunden a nodule 10 X 4 cm was observed. rON and SCHALLER On weathered surface it is always of a dull canary-yellow colour, most from N. Carolina. often appearing as by weathering hollowed, oval-shaped yellow nodules. surrounded by a On cleavages it is of a dull black colour. Dipped in acid it readily material of pitchy turns yellow, contrasting to the brilliant purple of heterosite, when laterial \yas found treated in the same way. Also streak and powder are of a dirty yellowish ter.» The authors tinge. 1 be forthcomina Cl Under the microscope the mineral shows itself to be remarkably en published since pure. Translucent in yellow to yellowish-green colours and in contrast where SCHALLER to heterosite, wholly unpleochroitic, it is crystalline in radiating fibrous lithiophilite from or globular aggregates. The refractive indices are a 1.760, y 1.775. lithiophilite and It was from the beginning apparent that this mineral represented another species of Fe - Mn phosphates than those dealt with above. Hne quantitative Pro£. A1\uNOFF of the State Natural History Museum therefore kindly isk. The coating allowed an analysis to be made by the chemist of the Mineralogical Dept., dr R. ELIX, which gave the result stated under 1 in the following 92 PERCY QUENSEL. [J an.-Febr. 1937. Bd 59. H. 1.
table. Analysis 2 refers to the mineral alluoudite, of DAMOUR (1848) doubted this which 1S nearly related both in chemical composition and field l'elatiollt> philite has 1 and to which I am inclined to refer the Varutdisk mineral. easily explail 1. 1 a. 2. course possi1:: Unsoluble . 1.24 0.60 for example H 0 - 2 101)0 0.24 tion during t H/) + 105" 0.66 0.037 2.65 Rpodumen caJ 11'e 0 19.83 O.l:ll 2 3 2G.62 , a substitutioI Mn 0 . 2 a 1.06 Na 0 in fres] MnO 28.17 0.379 23.08 2 MgO 1.17 0.030 0.00 In our case S1
Na2 0 7.20 0.116 0.47 albitisation c P205 46.70 0.287 41.25 A third exph F • 0.80 0.021 2 to below. 100.03 99.73 To begin v -0 for F. 0.19 fro 111. which t 99.84 and was mm Sp. gr. 3.576 Sp. gr. 3.468 prImary SoUl natrophilite 1. Alluoudite, Varutrask. the triphylit{ 1 a. Mol. prop. of d:o 2. Allnondite, Chantelonbe, France. emphasised t tbat they IT The analysis 1 works out satisfactory to the formula: along cleaval
5 Ra(P04 h Na(OH, F). At this sta by HEADDEN All Fe and Mn have then been reckoned as bivalent and enough Na 0 2 an analysis " has been deducted for H 0 105 and F. R represents MnO, Fe 0 2 + 2 a such as aUuo' l. and remaining Na2 0. Bases to P 2 0 5 are again nearly exactly 3 : shows all bat It is not strictly possible to reckon the old analysis from Chanteloube A search, analogously as the relatively high content of water has only been to try to find determined in the lump. As P 0 only suffices to bind the Fe - Mn 2 5 negative. It: oxides, enough (OH) must be deducted for Nal). An approximate eral I was in formula would then be I had asked 3 Ra(P04)2' Na(OH) associated wi again counting Fe as FeO. Though the two analyses show differencc:4, BERGGREN W these are hardly greater than can be accounted for by impurity of suce;edeed, af material in the older work. On the other hand, so much in general specimens of character and field occurrence is in common, that I believe the two It was soon. minerals to refer to the same species. found"
The original alluoudite from Chanteloube was supposed to be derived 1 Zeitschr. f. from triphylite through alteration. Already LACROIX1 has, however, 2 Zeitschr. f. < Am. Jonrn.
1 ~1in. de France IV p. 36ft
------_.. _--~------IJan.-Fobr. 1"37. f,d 59. IL 1.] MINERAI.S 0" '"IrE VARUTRASK PEGMATIT,. 93
?, of DAMOUR (1848)f: d bted this interpretation and is more inclined to presume that natro on and field relations I ~~ite has been the original source of alluoudite, which would more k mineral. ~ p sily explain tllP high content of Na/). On the other hand it is of ~:urse 2. possible to assume an independent invasion of Na2 0. whirh 0.60 ~or example naturally must. have. ac~ompanied the extensive albitisa tion during that epoch of mmeralIsatIOn. It may be remembered, how 2.65 spodumen ~an be alte.red to a mixture of eukryptite and alb~te, inferring 25.62 a, substitutIOn accordmg to BRUSH and DANAl from 7.62 L1 20 and 0.3!) 1.06 3.61 8.2H 23.08 NazO in fresh spodumen to Li2 0 and NaO in {3-spodumen. 0.00 In our case such a process is, however, hardly acceptable, as the epoch of 0.47 a,lbitisa,tion clearly preceeds the formation of the Li -- Mn phosphates. 41.25 A third explanation relating to a new mineral species will be referred to belo\v. 99.73 To begin with, I was at a loss where to seek the primary mineral, from which the alluoudite must be derived through partial oxidation, and was most inclined to accept LACROIX'S idea of natrophilite as the Sp. gr. 3.468 pnmary source. This idea was strengthened by the statement that natrophilite often occurs in closest association with the minerals of the triphylite - lithiophilite series. Already BRUSH and DANA2 have emphasised this, relating to material from Brancheville, and I noticed that they mention an auburn yellow secondary phosphate, found rmula: along cleavages of the natrophilite, which might well be alluoudite. At this stage my attention was however drawn to a mineral, described by J:-IEADDEN 3 from Nickel Plate mine, Pennington Co., S. Dakota with .t and enough Na 0 2 a,n analysis which might well represent the primary source for a mineral esents MnO, Fe 0 2 3 such as alluoudite. The analysis, given as no. 2 in the following table, rly exactly 3 : 1. shows all bases as bivalent and 7.46 Na 0 against 0.28 Li 0. s from Chanteloube 2 2 A search was now made on all material at hand from Varutrask ter has only been to try to find some rests of the primary mineral. The result was however bind the Fe - Mn negative. It is miss BERGGREN I have to thank for discovering the min An approximate eral I was in search of. She visited Varutrask in september 1936 and I had asked her to look out for a probably green phosphate, nearly associated with alluoudite, by now a familar mineral to us both. MISS s show differences, BERGGREN while making a collection of the minerals at the locality, for by impurity of mccedeed, after a good deal of searching in finding half a dozen small o much in general specimens of a dark green phosphate, closely associated with alluoudite. I believe the two It was soon evident that a new and distinct mineral species had been found. losed to be derived l 1 Zeitschr. f. Kryst. V p. 195. )IX has, however, 2 Zeitschr. f. Kryst. XVIII p. 11, 13. 3 Am. Jonrn. of Science 1891, XLI, p. 416. 94 PERCY QUENSEL. [Jan.-Febr. Hl3'7. Bd 59. H. 1.] The mineral is of a dull olive-green colour. It occurs in fine gran Na2( ular masses, in size and form about coinciding with the alluoudite. In one specimen one seemed able to follow a gradual transition to The small am alluoudite, and as this observation seemed to verify my assumption portions MnO: relating to the connection between the two minerals, material for For this min analysis was taken from this specimen. ken from the Under the microscope the mineral is colourless. Two well-marked HEADDENS pI cleavages at right angles probably are the t:\
Al20 3 0.36 0.005 It seams dif FeO 7.52 0.105 25.05 A reduction of 15.1i4 MnO 25.30 0.357 7.12 % without eaO 4.86 0087 5.53 plain. The pro MgO 0.00 1.50 (Mn Fe)O P20S Li20 0.88 0.030 0.28
Na2 0 7.12 0.115 7.46 imply that half
K 20 0.12 0.013 2.00 molecule have 1 P205 42.80 0.301 3~.64 In reference to F • 0.06 0.69 2 represent the S2 100.06 99.89 supposition she Sp. gr. 3.581. 3.612 parallf'l groups
1. Varulite, Varutra~k. centuated series 1 a. Mol. prop. of d:o . provisionally ID 2. Unnamed phosphate (Hcaddenite), S. Dakota. corresponding . lations. This s
2 As the ratios RO :R 20 3 again naturally are accidental, no definite R 0: RO 1: 5 formula can be expected, except reckoning all bases as bivalent. content in trip} Onc then gets ~lpp]'uxim 0.73 will presume that we may deal with the fully unoxidized phosphate, containing all bases as bivalent. It seams difficult to assume that natrophilite has been the source. 25.05 A reduction of Na20 from the theoretical 17.9 % in natrophilite to 15.1\4 7.12 % without any oxidation or hydration would be difficult to ex 5.53 1 1.50 plain. The proportions at hand are nearer the formula 1/2 Na2 0 2 / 2 0.28 (Mn Fe)O P20S than Li20 2(Mn Fe)O P20S in lithiophilite which would 7.46 imply that half the content of alkalies in, for example, the lithiophilite 2.00 molecule have been substituted for an equivalent amount of Mn-Fe. 3l:l.64 In reference to the proportions Mn -- Fe HEADDEN'S phosphate would 0.69 represent the same condition relating to triphylite. If in future this 99.89 supposition should be verified, we would have to reckon \vith two 3.612 parallel groups: the Li-series, triphylite-lithiophilite and a Na-ac centuated series, as yet represented by HEADDEN'S phosphate, which provisionally may be named h e add e nit e and varulite, the former corresponding to tripbylite; the 111,tt,pr to lithiophilitp in Fe: Mn rE' lations. This second series would be characterized by proportions idental, no definite R 2 0 : RO 1: 5 instead of 1 : 2, in the former series. The small Na bases as bivalent. content in triphylite, as documented in analysis 3 and also referred to on page 82, may well infer a primary intermixture of varullte. 7-310060. G. F. F. 1937. 96 PERCY QUENSEL. [Jan.-Febr. H);)7. This would also explain the occurrence of alluoudite in heterosite, alluded to on page 87. Regarding the relations of the whole group and the different stages of alteration, one might outline the following succession under progress ing oxidation: Li-serics. Na-series. Nagra or I. ~, 3. 4. trip hylite lithiophilitc headdenite varulite ~ ~ ~ ~ Fe-sickJerite Mn-sicklerite Fe-alluoudite Mn-alluoudite ~ ~ ~ ~ heterosite purpurite Na-heterosite Na-purpurite Biologer infor fnlg2 Spaced-out types are verified by analyses. Natrophilite has not been bredning t included, as analytical data of this mineral as yet only refer to one e11er har r single analysis of Brancheville material. Nothing gainsays, however, isfria stalI~ that the natrophilite series may be devided in Na(Mn, Fe)P0 and Na 4 det senare (Fe Mn)P0 subdivisions according to the relative proportions of 4 ryckte till}: Mn and Fe, each followed by its series of oxidation products in accord glacial e11e] ance with the scheme above. No such species are, however, as yet ha i detta known, and if the intermediate stages are missing, it would be difficult sig biologel to identify the terminating'alteration product from purpurite in general, over alIt tv as the alkalies would be missing and their character and proportions Fennoskan( to the other bases undefined. This refers also to Na-heterosite and Detkom Na-purpurite. biologerna Denoting the valency of Fe and Mn the relations of the minerals Detta gallel may be illustrated as follows: roras ides 1. 2. 3. 4. t vlagringar :2 2 :2 :2 2 2 :! 2 problemet, Li, (Fe, Mn)P0 Li, (Mn, Fe)p04 Na, 2} (Fe, Mn)2P0 Na 2} (Mn, Fc)2P0 4 4 4 oeh kartlagl ~ ~ ~ t ;j :2 :2 a ;j 2 2 ;l inom nagra (Li, Fe, Mn)P04 (Li, 1\ln, Fe)P04 (Na, Fe, Mn)P04 (Na, Mn, Fe)P04 ~ ~ ~ ~ oeh man h: 3 a ;1 a :l :l 3 :l generalisera (Fe, Mn)P0 (Mn, Fe)po4 (Fe, I\ln)P0 (Mn, Fe)P0 4 4 4 detaljiaktta; As mentioned, a subdivision of the natrophilite series might gIve uppfattning analogous groups 5 and 6. Ya8tra delen Min. Dept., Univ. of Stockholm, February 1937. Yisscrligen ( forskande a DONS, UND trakterna m 1'+llee,+ t'lld1 rag. 'lersoknin gel 1