American Mineralogist, Volume 58, pages 302-307,1973

Hureaulite,Mn,'* (H,O).[PO,(OH)],[PO'],:lts Atomic Arrangement Pnur BnlqN Moonn nNn Tlrenanu Anexr

Department ol the Geophysical Sciences, The Uniuersity ol Chicago, Chicago, Illinois 60637

Abstract

Hureaulite, Mnuz*(H"O),[POB(OH)].[PO4h,a 17.594(10), b 9.086(5), c 9.404(5), P 96.67(8)', Z - 4, spacegroup C2/c, is one of the more persistentlow temperaturetransition metal phosphate hydrates derived from hydrothermal attack of triphylite-lithiophilite. The structure was solved by Patterson and difierence synthesisand least-squaresrefinement con- vergedto R(hkI) - 0.058 for 3500 reflections. The structure is based on an octahedral edge-sharingpentamer of point symmetry 2 which has composition MuQ,". It further links at six corners to produce an open octahedral framework of composition MuQ,, where @ = 4 water molecules { 14 oxygens associatedwith the [PO']'- tetrahedra.One tetrahedron, [PO"(OH)], possessesa free hydroxyl group situated in a pocket in the structure. This pocket may spatially accommodatean intermediate-sized cation, extending interest to the series Mn"'-(H,O)"PO"(OH)1, [PO,]B - X'*Mn"'*(H,O)n [PO4]"[PO']'and may explain the excessof larger cations in some analyses.Me-O averagesare Mn(1)-O 2.19,Mn(z)-O 2.16,Mn(3)-O 2.2r,P(1)-O 1.54and P(2)-O r.54A. Hureaulite characteristically occurs very late in the secondary phosphate paragenetic sequence.Since nearly all iron is oxidized to the Fe3* state before its crystallization, most natural hureaulitesare Mn-rich compoundsalthough extensive(Mn,Fe) solution is known for synthetic material.

fntroduction Experimental Hureaulite is one of the more persistent and wide- A superior single crystal of hureaulite, slightly elongate spread phases of the aquated first transition series prismatic in shape, averaging 0.1 mm in thickness and 0.2 mm in length, was selectedfrom a personally collected phosphates associatedwith hydrothermally attacked sample from the White Elephant pegmatite,between Custer triphyliteJithiophilite crystals in granite pegmatites. and Pringle, South Dakota. The crystal was mounted Interest is added to the speciesas a result of numer- parallel to the c-axis and 420O reflections were gathered ous reports on its synthesisand the recent discovery on a pIcKER automated diffractometer utililizing graphite MoKa radiation (I - 0.7093 A). The of the isotype sainfeldite, Cau(HrO)n [AsOa(OH)]z monochromatized very small mosaic spread (f0.18") and least-squares [AsOr]z (Pierrot, 1964) . Sainfelditecrystallized frorn refinement of 12 reference reflections guaranteed high arsenate-bearing solutions derived from mine waters quality data. Cell parameters resulting from the refinement acting upon arsenides and subsequently reacting with appear in Table 1. Twenty second background counting carbonates associated with late stage fissures. The times were taken at each side of the reflection, with a scan sainfeldite clearly is a post-mine product and formed rate of l.O"/minute and half-angle scansof 1.8". Shells of gathered to maximum 20 - 75'. closeto room temperature. reflections were The data were processed by conventional computational To understand the labyrinthine world of aquated proceduresto obtain a table of lF(obs) l. No absorptioncor- transition metal phosphates,three-dimensional crystal rection was applied on account of the favorable size and structure analysis is necessary. The underlying goal shape of the crystal (u = 48.6 cm-'); omega-scansabout in these studies is to establishthe nature of the poly- selected reflections revealed that such a correction would be minimal. Remaining were 3500 symmetry independent hedral clustering of the transition metal octahedra reflections including the averaged symmetry equivalent data. and the role of water and hydroxyl groups in these structures. Only in this manner can an unambiguous Solution of the Structure structural classification evolve and a link be estab- The hureaulite heavy atoms were located by three- lished between the clusters in the crystal and those dimensional Patterson synthesis.Included were three which existed in the solution from which the crystals non-equivalent manganese and two non-equivalent glew. phosphorus atoms. Routino inspection of the Pat- 302 ATOMIC ARRANGEMENT OF HUREAULITE 303

Tesls 1. Hureaulite. Crystal Cell Contents' finementconverged to R(hkl) : 0.058 for all 3500 reflections. e (8) u .sgr+(r0) Final atomic coordinate parametersand isotroPic ud) e.086(s) thermal vibration parametersare given in Table 2 s (8) e.404 (s) o and a list of appearsin Table 3.'z g so.oz 1sy lF(obs)l-F(calc) space glggP c2/c Geometryand Topology of the HureauliteStructure z u- fomla (ho.zqF"o.zo) slurol u [0, toU],[rou], Condensationof the octahedral modules. The speciflc gravity 3.r7 underlyingfeature of the rather complicatedhureaulite density (calc.) gnlcm3 3.24 structureis an octahedraledge-sharing pentamer. Such lsmple from White Elephmt pegmtite, Custero South Dakota. seriesM,Qn,*, Octahedral cations detemined frcm ARL electron prole a pentamerbelongs to the homologous aalysis. The specific gravity was obtained with a Bemn where M : octahedral core and : octahedral nicrobalance. Q vertex of which there are / cores and 4r f 2 vertices. This homologousseries is identical to the connected tersonmap revealedthat one Mn atom wasconfined tree of edge-sharinghexagons without loops or to the 2-fold rotor at O, y, lq since all potential circuits and, in hureaulite, has the composition positionsat inversioncenters, also of equipointrank MuQ"r. As idealized in Figure 1, the pentamer has number4, werevacant. Since this atornhas only one point symmetry 2. Individual pentamersare further degreeof freedom,the Mn(1)-Mn(2) and Mn(1)- condensedto symmetry equivalent pentamers via Mn(3) vectorscould be locatedwithout difficulty. cornersharing through the O(5)and C(10)atoms, and The solutionsof Mn(2) and Mn(3) were further Figure 1 revealsthat four O(5) and two O(10) atoms obtained by tabulating the Harker lines as solutions are associatedwith each pentamer. This fusion of -+ in (2x,2y,22) followed by a search for the in- pentamersresults in a very looseand open octahedral versionpeaks at the intersectionsof thesesolutions. framework of formal composition MrQrg, where When the Mn(1), Mn(2) and Mn(3) atomswere 'To found, all Mn-Mn' vectors were located and elim- obtain a copy of Table 3, order NAPs Document Publications, Division of inated.The P(1) and P(2) atomswere located by Number 2024 from Microfiche Microfiche SystemsCorporation, 305 East 46th Street,New examiningstrong vectorsremaining within a shell of York, N.Y. 10017.Please remit in advance$1.50 for micro- radius 3.7 A from the origin, correspondingto the fiche or $5.00 for photocopies.Please check the latest issue sum of Mn-O (2.2 A) and P-O (1.5 A) distances. of this journal for the current address and prices. The solutions for the P atoms were obtained from Atomic Coordinates and Isotropic the solutions of the Mn atoms. It was a delightful Teste 2, Hureaulite: Thermal Vibration Parameters* way to spendtwo hours on a rainy afternoon. Two cycles of atom coordinaterefinement of the Aton v z s(R2) three Mn and two P atomsconversed to Mn(r) 0 0.r0238(8) 3/+ 0.6e(r) rft(2) 0.31696(3) .08821(6) -.31470(6) .67(r) )llF(obs)l- R(hkt) : lF(calc) _ 0.41. l,ln(3) .17qs3(3) -,02833(6) -.13408(6) .7r+(I) ) lF(obs)l P(r) . r+uz3(5) .32038(9) -.0e00s(e) .66(r) P(2) .160e8(s) .26066(e) -.37176(e) .60(r) All ten oxygen atoms were located by subsequent o (r) .34ss(2) .2278(3) -.1338(3) r.r3(4) differencesynthesis. - 0(2)=(0D .4884(2) .21s0(3) -.0796(3) r.2q(r+) -.2072(3) Refinement o(3) .423I(2) .433r(3) r.U(t+) o (q) .41s6(1) .3ers(3) .0ss8(3) I.0s(t+) Refinementof the atomic coordinatesand isotropic o (s) .1638(r) .2357(3) -.s33r(3) r.00(3) thermalvibration parameters proceeded without dif- 0(6) .0760(r) .26ss(3) -.3rt07(3) .96(3) ficulty, using a local version of the oRFLs program 0(7) .201s(1) .4040(3) -.3257(3) 1.or(4) for rnu 7094 computers by Busing, Martin and o(8) .2024(r) .r326(3) -.288s(3) .s3(q) Levy ( 1962). Scatteringcurves for Mn*, Ps-and O- 0(e) =E2o .4213(2) -.0081(3) -.3q63(3) r.70(S) were obtained from the tabulations of MacGillavry 0(I0)=H2o .2ses(I) .07e6(3) .0310(3) 1.0s(4) (1962). and Rieck Final full-matrix atomic param- * Estimated standard errors in parentheses refer to the eter and isotropic thermal vibration parameter re- Iast dipit. 304 P. B. MOORE AND T. ARAKI

O(2) is interpretedas an acid portion of the struc- o(|of ture, with the P(1) tetrahedralgroup written as lPos(oH)1,-. A curiousand potentiallyimportant feature of the acidpocket is its spatialproperties. From our Fourier syntheses,we concludedthat the site is empty, at least in the crystalwe studied.In addition,a probe analysisshowed only Fe and Mn were presentas largecations and thesetotalled to 4.96 in the formula unit. Defining its approximatecenter as the empty positionX in Figure 2, thereexist six bondsoccur- 0b ring pairwiseto O(2), 0(6) and O(9) with a polyhedral a distortedoctahedron. Ftc. 1. Idealizations of the octahedral pentamer in hureau- shaperesembling lite. a. Down the e*-direction, showing the 2-fold rotor TheseX-O distancesinclude X-O(g) 1.56,X-O(z) and the six points of corner-fusion to other symmetry equi- 2.55 andX-O(6) 2.7I A. O(9) is a terminalwater valent pentamers. b. Down the y* direction showing the molecule,bonded to Mn(2), the terminus point- 2-fold rotor, Unshaded octahedra are all above (or all ing into the pocket. Allowing sorne flexural free- below) the plane of the ruled octahedron. dom for O(9) and some "sliding" of X along the two-fold rotor, it is not difficult to conceivepartial to completereplacement of X by intermediate-sized Qra : 4o,' + l4o', On beingwater moleculesand Op oxygen atoms associatedwith the (POn)3-tetra- cations,such as Li*, Na* Ca2*,etc., neutralizingthe hedra. All water moleculesin hureauliteare bonded acid characterof the crystal. This argumentis ad- to the transition metals,so behaveas ligand groups. vanced further to explain two analyseswhere an Sincethere are no "zeolitic" water moleculesin the excessof larger cationsis reported. structure,the formula shouldbe written Mn5'z*(HrO)4 [PO.(OH)]rPOol,. One oxygen atom associatedwith the P(l) atom is not bonded to any transition metal and remains an (OH)- group in an open pocket in the structure and participatesin hydrogen bonding. Thus, hureaulite is an acid crystal. Of the oxygen atomsassociated with P(1),O(3) and O(4) bond to two, O(1) to one, and O(2) to no transition metals. For P(2), O(5), O(7), and O(8) bond to two and 0(6) to one transition metal. Figure 2 reveals the rather elegantstructure down the z* direction. The phosphatetetrahedra further knit the octa- hedral pentamerstogether by bridging to symmetry equivalent pentamersgenerated by the c-axial glide operation and the inversion centersat y4, /o, O; etc. Bvt no "' O-P-O-M ". bondscross the a-axis at x = 0, Vz;this promotesthe good {100} cleavage observedfor hureaulite. The acid pocket. The O(2) : (OH)- groups point into an open pocket in the structurewhose cen- ter is on the 2-fold rotor at Vz, y,3/+; etc., where ! - O. Two geometricallyplausible hydrogen bonds can be described,as revealedin Figure3. The bonds Ftc. 2. The hureaulite structure down the z*-direction. O(9)-H'"O(6)"' 2.703A andO(2)%H...O(9) Remaining symmetry equivalent polyhedra in the cell are 2.714A occurwithin the pocket.But O(2) doesnot generated by the c-glide operation. Points of fusion of the pentamers are drawn as black dots. The MnO,noctahedra are appearto receiveany bonds,since the secondnearest the (POn)* P-O spokes. '.O(2) stippled and tetrahedra appear as distanceis O(9)-H. 3.330A. Accordingly, The X-O bonds are dashed in. ATOMIC ARRANGEMENT OF HUREAULITE

HureauliteParagenesis in Light of Its Crystal Structure Hureaulitewas originally namedby Alluaud (1826) o(t)"+0.37 and describedby the miningengineer Dufrenoy (1829) and its first analysiswas undertaken by Vauquelin (1825). Material occurred sparingly from Hureaux, Haute Vienne,France, and later from La Vilate near Chanteloube,as describedby Des Cloizeux(1858) who also presented crystal drawings. Subsequent L occurrencesinclude the famous,Branchvillepegmatite, b=0 Fairfield Co., Connecticut(Brush and Dana, 1890); otzf*o.eo the Stricklandquarry, Portland, Connecticut (Schairer, 1926): and the Stewart mine, PaIa, California Frc. 3. Proposed hydrogen bonding scheme for hureaulite. (Schaller,1912). Fisher (1964),in his study of lithian Arrows point to the oxygen acceptors. Heights are given hureaulite("bastinite", Fisher, 1946)from the Custer as fractional co-ordinates of the z-axis. Mountain lode,near Custer, South Dakota, established the synonymy of "palaite" (Schaller, l9l2) with the Hydrogenbonds. The O(9) and O(10) water species; and Strunz (1954) relegated "baldaufite" moleculesare donors of hydrogenbonds. Probable and "wenzelite" from Hagendorf,Bavaria, to varietal . .O(7)' contributionsby O(10) areO(10)-H. 2.78 status. "Pseudopalaite"of de Jesus (1933) from . .O( andO(10)-H. l) 2.65A with an angleO(7)'- Mangualde,Portugal, was also shown to be hureaulite O(10)-O(1) 117.9'. O(9) is more difficultto by Mason (1941)who adds Eriij?irvi,Finland, as a assess.The geornetricallymost compatibleconfigura- new location. Indeed,few mineralshave enjoyed such ..0(6)"' tion is O(9)-H. 2.70 and O(9)-H... a reputation for obfuscationin the literature! O(I)"' 3.50A with an angle0(6)"'-0(9)-0(I)" Recently,hureaulite has beenrecorded and noted 92.6".It may be arguedthat O(2) receivesas well from many localitiesand the speciesis one of the as donatesa bond from O(9), but the angle0(6)"'- more persistent of the transition metal phosphate O(9)-O(2) 140.3"is way out of range,even for a hydrates.Roberts and Rapp (1965) record six lo- distorted tetrahedral angle. calitiesfrom the Black Hills, and oneof us (P.B.M.) It appearsthat the most likely acceptorsof hydro- has collected specimensat nearly every pegmatite gen bondswould be O(1) and 0(6), further sub- where altered triphyliteJithiophilite crystals and stantiated by the electrostaticvalence balance cal- their hydration products are in evidence.It was culations in Table 4 and the polyhedral interatomic common in the altered triphylite crystals at the distancesin Table 5. Disregardingthe contributions by hydrogenbonds, both O(1) and 0(6) are se- (2) verely undersaturatedwith respect to coordinating Tesrn 4. Hureaulite. Electrostatic Valence Balances of Cations about Anions cations,with Al : -0.42. But the Me-O(l) and Me-O(6) distancesare not amongthe shortestfor E their polyhedra, so their degree of undersaturation o(I) P(r) + ['ln(z) r.58 is probably relieved by the hydrogenbond contribu- o(z)=(oH)- P(I) r.25 tions. Polyh.edraldistances. The Me-O averagesare o(3) P(I) +l,ln(I) +Ih(3) I.9 2 Mn(1)-O 2.19, Mn(2)-O 2.1.6,Mn(3)-O 2.21, o (4) P(r) +Mn(I) +l,rn(3) 1.92 P(l)-O 1.54 and P(2)-O 1.54A, which compare o (s) P(2) +r{n(z) +Mn(3) L.92 favorablywith the Mn-O 2.22 andP-O 1.57A aver- o (6) P(2) + Iln(l) r.58 ages based on the tables of Shannon and Prewitt o (7) P(2) +!tn(z) +Mn(3) r.92 (1969) and the numerousrecently refined man- o (8) P(2) +Mn(z) +lan(3) I.9 2 ganesephosphate structures. In addition, Table 5 =Hro revealsthat shared octahedraledges are among the o (9) Mn(2) 0.33 shortest individual polyhedral distances,about 10 o (10)=xr6 I,er(z) + ltr(3) 0.67 percent shorter than the polyhedral edge averages. 15.0I 306 P. B. MOORE AND T. ARAKI

Tesre 5. Hureaulite: Polvhedral Interatomic Distances* with ratiosof 1.25and 1.50respectively. This peculiar series is possible becausethe acid pocket in the S!.gL ls!cbedrs w structureat l/2, -0, l/4 of equipointrank number4 -o(3) -o(e) -0 (s) ' ' 2 Mn(l) "2.u.6 I l'{n(z) z.oez I Mn(3) z.rzs I cations 2 -0(r+)I 2.216 -0(8) 2,O97 -0(8) 2.1s8 is dimensionallysuitable for intermediate-sized 2 -0(6) &33?_ -0(r) 2.r34 -0(3),' 2.170 like Na*, Li', Ca", etc.Thus, Volborth suggestedthe , average Z.tgg I -0(7)",2.I81 -0(4) 2.208 for his compound -0 (s), 2.I98 -0(r0) 2.2s6 compositionCaMnu(POn)4.4H2O 2 0(3) 'r-0(r+) ' 2.729 -0 (r0) ' ,ag?!!_ -0(7),i,3J3I_ which is, in effect, a neutral salt. To confirm the i '-0(3)v,2.eos r 0(3) average 2.159 average 2.209 existenceof a neutral salt for hureaulite, a most 2 0(4) ' -0(6) 3.02s '-0(6) i '-0 2 0(3) ' 3.0s3 0 (7) ' (I0) I r2.778 careful analysis of cations and water content or a 2 0('+)I -0(6)v 3.2U o (7) , , '-o (s) 2.8o7^ difference synthesison the structure of Volborth's r 0(6) -0(6)v 3.337 0(8) -0(r0), '2.832 2 0(c) ' -0(3)v,3.416 0(r) -0(8) 2.8e0 material would be necessary. average 3.093 0(7)','-0(e) 2.e63 Paragenetically,hureaulites are eitherproducts of i ,3.010 0 (e) -0 (10) primary phosphates,partic- 0(e) -0(s), 3.0q3 hydrothermalattack on 0 (r) -0 (7) , , 13.070 ularly the triphyliteJithiophiliteseries, or the reac- 0 (I) -0 (s) ' 3.13r{ products phosphaticsolutions during 0(s) ' -0(8) 3.27D tion of Mn-rich 0 (r) -0 (e) 3.3rs the late hydrothermalstage which were independent ,,3.3ee 0(s), -0(10) of the existenceof some parent phase.Of interest ave?age 3.0t+3 is the synthesisof hureaulite-typecompounds by Distmces to Xr the chter of the Klements et al. (1970). By hydrolysis of metal pall +o+rrhairfn P(21 tet"ahedlon vactut acid Docket r1r1-01:; r.srz I P(2)-0(7) 1.s27 2 x-0(9) r.s6 chlorideand sodiumdihydrogen phosphate solutions -0(4) r.s20 -0 (8) r.s38 2 -O(2) 2.ss at intermediatepH, they were able to synthesize -0(1) -0(5) -0(6)'t r.s3r I.sr+0 2 2.7L mixed crystalsof Mn2*,Fe'- (Co'., Zfl'*, Cd't, and -0(2) L5ZL_ -0(6) f..55.q_ average I.535 average I.5q0 Cu'.) hureaulites.Solid solutionof Fe'* in Mnz* ap- 0(r)-0(3) 2.4s7 0(7)-0(8) 2.4e0 percent 0 (2) -0 ('+) 2.49'l 0(s)-0(8) 2.s03 pears limited with maximum reported 35 0 (1) -0 (2) 2.soe 0(s)-0(7) 2.s07 replacement,which is the upper limit reported in 0(3)-0('+) 2.s2I 0 (s) -0 (6) 2,szs Hureaux. But most 0 (2) -0 (3) 2.s23 0(6) -0(8) 2.s28 the analysisof hureaulitefrom 0(r)-0(4) a:3I_ 0(6)-0(7) al:z_ natural hureaulitesoccur in assemblageswhere the average 2.506 average 2.51S mineral is clearly contemporaryto or postdatesthe The primed flpersc?ipts refer to the follmirE trasfomations per- fohed on the parffieters ln Table 2: t=Uz-x, U2-y, Z; t'+,i, appearanceof the basic ferric phosphatessuch as Vz+zi | | t=V2-x,V2+y,V2-zi te=VZi,V2+4 v=A,y,V2-z: vr=U2+4, vtt=*r1,2. Vz+y,zi Estimted standard errcrs: M-O, P-O j 0.003 X; strengite,rockbridgeite, etc., and are consequently 0-0, + 0.004a. aoctahedral content comparedwith the triphylite par- shareal etlges. low in Fez* ent phase.Where lithiophilite is the parent phase, Fletcherand PalermoNo. I pegmatites,N. Groton, hureaulite forms directly as drusesupon the parent New Hampshire,and from a pegmatiteat CoosaCo., without the appearanceof the ferric compounds. Alabama(P.B. Leavens,pers. comm.). Of considerableinterest are the analysisby Volborth Tesre 6. Hureaulite: Analyses with Excess Large Cations (1954) on hureaulite from Viitaniemi, Eriijiirvi, central Finland, and the analysisreported by Fisher L2 Weight percent Cations (T=16) Vieiqht percent Cations in cell (1964)on the lithian hureaulitefrom the Black Hills. NaZo 2.92 Both analysessuffer faults: Volborth's material was Hzo 2 t rn ? contaminated with minor morinite (but he reports cao 8.58 4.q not > 0.7 only a trace of AlrO, !) and the water determination Mco 23.t+ not > I.7 was by difference, r.ho 38.85 L5.7 and Fisher's analysesare crude. f eO I.4r+ 0.6 Table presents l-. q 6 theseanalyses and computationsof Beo 1.35 16.0 u?i?. rtiq cations based on 16 tetrahedra (: P * Be) in the P2OS 36.35 14.6) former and the crystal cell in the latter analysis.The qo(-) 0.0r+ HzO(*) 10.00 ratios 2 large cations:27 cations are 1.46 and 1.47 rm. 0.75 respectively,and extend our interest to the series (100.28) lAnalysis of volborth (195tt). T = Be2* + p5+= 16. H2o(+) was M5'*(H'O)nlPOs(OH)LlPO4l, detemined by difference. 2tishe! (1954), conputed using his g 17.6a 8, ! 9.I3, g 9.49, g6"fO' = € od specific gravity 3.2I. The two indep@dent analysea and x'*Mu'*(Hro)4[poa]dpo.l, for P are in confLict. ATOMIC ARRANGEMENT OF HUREAULITE 307

This is the paragenesistypical for Branchville, Con- Drs Clotzeeux (1858) Determination des formes cristal- necticut, and Custer Mountain, South Dakota, peg- lines et des propri'6t6soptiques de I'Hureaulite. Annal. Chim. Phys. Ser. 3., 53,293-302. matites.Strunz (1954) observedthat hureaulite from DurnENov (1829) Sur deux nouveaux phosphatesde man- Hagendorf Sijd has an Fe:Mn ratio of 1 : 3 whereas ganeseet de fer. Ann. Chim. Phys. 41,337-345. that of the parent triphylite was nearly 3: I. Con- FISHER,D. J. (1946) Bastinite, a new pegmatitephosphate sistent with the synthetic studies on hureaulite, the (abstr.)Amer. Mineral.31, 192. species evidently appears at the final stages after (1964) Lithian hureadlite from the Black Hills. oxidation of iron to the ferric state and after pre- Amer. Mineral. 49, 398-406. cipitation of such species as rockbridgeite, leuco- Krr,lrr.Nr, R., M. MErNnoro, H. SreNc, eNo G. SrBNrs (1970) Bildung von Mischkristallen bei Verbindungen phosphite and strengite. For the hureaulite in this vom Hurdaulite-Typ. Z. anorg. allgem. Chem. 377' study (Table 1), the Fe:Mn ratio is basedon elec- I 35-l 38. tron probe analysis and the White Elephant parent Mec Grrrevnv, C. H., eur G. D. Rrecr (1962) Inter- phase was unquestionably an iron-rich triphylite. It national Tables for X-ray Crystallography, Vol. 3. The is concluded, as it was by Strunz, that the manganese Kynoch Press,Birmingham, England. content of the solution is enriched as the ferric iron MrsoN, B. H. (1941) Minerals of the Varutrdsk pegmatite. XXIII. Some iron-manganesephosphate minerals and is removed by precipitation at higher temperature. their alteration products, with special reference to ma- What ferrous iron remains enters into solution at the terial from Varutrdsk. Addendum. Geol. Fiiren. Fcirhandl. final stage in the predominantly managanese-rich 63, 174-175. hureaulite and is limited to a Fe:Mn - 1:3 ratio Pnnnor, R. (1964) Contribution ir la min6ralogie des as observedin the synthetic studies. ars6niates calciques et calcomagn6siensnaturels. Bull. Soc. Fr. Miniral. Cristallogr.87, 169-211. Acknowledgments Roeenrs, W. L., ,qNpG. Rrpp, Jn. (1965) Mineralogy of the Black Hills. S. Dak. School Mines Technol. Bull. lE, Dr. Jo Ann Molin-Case assistedin the collectionof three- 1I 1-113. dimensionalintensity data and Mr. G. R. Zechmannper- Scnernrn, l. F. (1926) Lithiophilite and other rare phos- formed the electronprobe analysisfor the large cations. phates from Portland, Connecticut. Amer. Mineral. ll, We appreciatethe continuedinterest of Mr. W. L. Roberts 101-104. and Dr. D. H. Garske,whose extensive experience and Scne.nrn, W. T. (1912) New manganesephosphates from guidancein Black Hills pegmatitelocalities have provided us with exceptionalspecimens. the gem tourmaline field of Southern California. l. Wash- This study was supportedby the NSF GA-10932grant ington Acad. Sci. 2, 143-145. awardedto P.B.M. and an AdvancedResearch Projects Sru.wNoN,R. D., eNo C. T. PnewIrt (1969) Effective ionic Agencygrant administeredto the Universityof Chicago. radii in oxides and fluorides. Acta Crystallogr. 825, 925-946. References SrnuNz, H. (1954) Identitet von Wenselit und Baldaufit mit Hur6aulith. Neues lahrb. Mineral. Moncrtsh. 1954, Alr-ueur (1826) Noticessur I'H6t6rosite,l'Hureaulite (fer 166-r'17. et mangandsephosphat6) et sur quelquesautres mineraux VruqurrrN (1825) Analyse de I'Huraulite, minEral trouv6 du Departmentde la HauteVienne. Ann. de Sci.Nat.8, Ann. Phys. Ser. 2, 134-354. dans la commune d'Hureaux. Chim. 30.302-307. Bnusn,G. J., lNn E. S. DlNe (1890)On the minerallocal- (1954) Lithium- ity at Branchville,Connecticut: Fifth paper.Amer. l. Sci. Votnontn, A. Phosphatmineraleaus dem 39,201-216. pegmatit von Viitaniemi, Eriijiirvi, Zentral-Finnland.Ann. BusrNc,W. R., K. O. MenrrN,AND H. A. Lew (1962) Acad. Sci. Fenn. III. Geol.-Geogr.Ser. A, 39' 5-90' oRFLs,a Fortran crystallographicleast-squares program. U.S.Nat Tech.Info.,Sero. ORNL-TM-3OS. Dn Jr,sus,M. A. (1933) PegmatitesmanganoJitiniferas da Manuscript receiued,August 10, 1972; acceptedfor regiaode Mangualde.Portugal Seruicos Geol. 19,65-158. publication, September25, 1972.