New Data for Kottigite and Parasymplesite B. D. Sturman

Carwdian Mineralogist Vol. 14, pp, 43744t (1976)

NEW DATA FOR KOTTIGITEAND PARASYMPLESITE B. D. STURMAN

DryL ol Mineralogy and Geolagy, Royal Ontario Museurn, 100 Qaeen's Pok, Toronto, Ontarlo, MSS 2C6

ABSTRACT INTRoDUCTIoN Microprobe analysis of kiittigite from the type The Royal Ontario Museum recently acquired tocality (Schneeberg Germany) gave the formula a beautiful specimen of blue crystals, labelled (Znz.arCoo.egNio.ra)>- a(Asoa):. 8HzO. The mineral ktittigite, from Ojuela mine, Mapimi, Mexico. is light red to carmine red, streak reddish, perfect During routine examination of the crystals, it cleavage,hardness 2-3, Dau 3.245/cm3. It {010} became evident that data for kiittigite, available is biaxial (+), 2V : 85o, no 1.619,np L.645,nn in the literature, either incomplete or are 1.681,X : b, Zltc : + 32", Pleochrois is weak, ab- are sorption Z < Y : X. Unit-cell dimensionscalcu- not reliable. For example, the two sets of op- lated from powder diffraction data are a I0.24O, b tical data available (Larsen 1921; \ilolfe 19210) 13.401,c 4.752i, 9LO5\7" Z:2. are not in agreement and both were determined Blue crystals of supposedkOttigite from the Ojuela on unanalyzed specimens. Also, the two strong mine, Mexico (Larsen 1921) are parasymplesite.Mi- lines .sharacteristic for the vivianite group are croprobe analysis gave a formula (Fer.osZnr.ar)>=a missing in the kiittigite powder diffraction pat- (AsOa)z.8HzO.Crystals are pale blue, with very pale tern (JCPDS card #l-744). Consequently, the blue streak, perfect {0101 cleavage hardness 2-3, blue crystals from Mexico, and a Royal Ontario D*r. 3.13g/cm8,D-o* 3.12g/crn3.The mineral is Museum specimen of kiittigite from the type biaxial(+), 2V : &, not.6?.0,np L.648, L.ffii, ry locality (Schneeberg, Germany) were analyzed. X : b, Zltc : *29'. Pleochroisrn is weak, absorption X> Y: Z. Unit-celldimensionscalculated Microprobe analysis of the crystals from Mexico powder pattern showed these to be par.asymplesiteFeg(AsOe)s' fto- lh" are a L0.276,D 13.,180,c 4.77LA,p 105'01f,spacegroup CZ/m; Z : 2. 8HrO, with large amounts of Fe replaced by Zn. The Museum specimen from Schneeberg is kdttigite, Zng(AsOn)r'8ILO, with only a small SoMMens amount of Co and Ni. I"a kiittigite tlTe de Schneeberg(Allemagne) donne, i la microsondgla formule (Zng.scoo.a2Nio.rr)>:u Kiirrrcrrr (AsOr)2.8HrO.De couleurrouge p?le i rowe carmin, rougeatre dans la rayure, elle possBdeun elivage Kiittigite crystals on the Schneeberg specimen parfait {01.0}et la duret6 2-3. Sa densit6calcul€e est in the Royal Ontario Museum (ROM specimen : D. 3.24, Elle est biaxe positive, avec 2V : &5o, No. M15537) are less than 0.3 mm in size. Most : - ,to 1.619,np 1.645,n1 1.681;X b, 7 6 s 132'l of the kiittigite is a crust over altered rock; a faiblementpl€ochroiqugabsorption Z Y: X. > few protrude Les dimensionsde la maille, calcul6esi partir de small crystals which through the donn6esde diffraction (m6$hodedes poudres), sont: crust in several areas give signals too poor to allow measuremeits on the optical goniometer. a tO,24S,, 13.4,01,c 4.752!^,P 105'7t, d'ot Z : 2, The with Des cristaux bleus de la mine Ojuela Mexique), fornis listed in Table 1 were observed, identifies commekdttigite (Larsen 1921)sont en fait the universal stage, on tlree crystals. de la parasymplEsite.La microsondedonne la formule Kdttigite crystals are elongate parallel to (Fer.osznr.s2)>-g(AsOa)z.8Hso.De couleur bleu [001] and flattened on {010}. The most com- pile, tr6s pale dans la rayure, i clivage parfait {010} mon habit is shown in Figure la. et de duret6 2-3, cette parasympl6sitea pour densitd calcul€eD, : 3.13,mesur6e D^ : 3.12.EIle est biaxe positive, avec,2V = 86o, nn L.620,np 1.648, n1 TABLEt. ANGLETABLE FoR KoIIrcITE, scHfiEEBERo,oERtFrt 1.685,X - b, Zltc - + 29"; faible.mentpl€ocbroique, rcnocflnlc,a.10.240 ,=13.401 8.105'07' absorptionX > Y : Z.Le dimensionsde la maille, "-q.ISZA calcul6esi partir du diaEamme de posdre, sont: observed cal cul ated a 10.276,, 13.480,c 4.7714,B 105' 0lr, d'a\ Z : 2; ,010 0 90' 0"00' 90'00' le groupespatial st C2/ m. n ll0 55' 90. 53.35' 9f'00' 890 50 112" 90" 50'55', " ?:l -47" -44'16' (Traduit par la R6daction) 44" 44'43' 437 438 TIIE CANADIAN MINERALOGISIT

'i----"- i

)jp" ./' l'

b Frc. l. (a) The cornmon shape of kitttigite crystals from Schneeberg,Ger- many; (b) the orientation of tie optical and crystallographic elements for kiittigite crystals lying on {010}. TABLE3. X-MY POI,IDERDIFFRAC1ION DATA FOR KOTTIGITE Physical and. optical properties rest dcalc hkl rest d*aa dcal IlkL dobs c Kiittigite is ligbt red to carmine red, with the 70 7.87 7.95 ll0 t5 2.0782.O79't.956 350 streak being reddish white. Hardness is 2-3. 100 6.66 6.70 020 30 I.956 'r.954 510 There is a perfect cleavage.Density was 20 4.93 4.94 200 Toz {010} 5 4.59 4.59 001 25 I .914 'I1.912 132 not determined because of tle small amount of 40 4.385 4.393 Tll't30 5 I .902 .900 20? 'I 4.080 4.071 r.839 clean sample available. The calculated density, 3.983 3.978 220 l5 1.689 3',24 g/cm8, is smaller tlan tle value of 3.32 30 3.909 3.909 Zor'n]' '10l0 1 .677 3.652 3.656 1.662 given by Wolfe (1940) because the unit-sell 3.220 3.221 T3l 1.651 dimensions, calculated from the powder diffrac- 20 3.195 3.200 310 I 1.623 3.006 3.006 5ll '10 1.614 tion pattern, are larger. 90 2.994 2.995 201 I .601 1 2.771 2.773 240 20 1.56t Orientation of tbe princrpal vibration direc- 60 2.734 2.734 221 10 I .544 20 2.706 2.745 041 5 1.531 'I.BLE2. uNlT;pELLDltrlENst0Ns, opTlcAL AND pHystcAr coNsrAnrs oF 30 2.65't 2.652 330 2 l.tto rcTT1OITE.FROI.I SCHNEEBERG, GERI'IAN 5 2.546 2.54{ 241 30 1.499 50 2.462 2.460 40l 1.484 1 Thls study Lanen llo l fe , 20 2.338 2.338 T12 ,462 n92l) (1940) 25 z'r" 2.325 z0? 1.450 'r0.240(6) z3z2 T5l 1.423 l0. n l0 2.31? 2.309 421 I.418 1,: b 13.40r(8) 1t tl 4,70 'I , ,1r 2.234 060 1.39t ',1 4.752(2) B 105.07,(2) 103050' 2.233 241 1.361 (2/.n 1.346 Spaae grcup...... C2/n 25 ?.196 2.196 2zz 2 2 2 t5 2.089 2.090 ll2 1.264 I .219 freas :. t-g/on: 3.33 g/q{ 1.188 ,.al c :,zi-gl",P 3.32 g/cnr R z-3 2.5-3 2.5-3 Guinier carera Cu,(dradiation, intenslties estjmted visually. 't.622 FRott 'r.645r.61e(1 ) | .662 'I TASLE4. cHEt'il$r coilposlTloN0F KUTTrctrE SCHilEEBERG,cER!{ANy (r) t.06 '1.671.638 l.6sl (t) 1 .717 .l zn0 33.6 32.32 zvz reas. 85" (1) 74. a2og [37.17] 37.42 .2va-ca\c... 83' 77' 72" orspeEion t

TABLE5. ISIOLETABLE FOR PAMSYIIPLESITE tions and optic axial augle were dete@ined on mnoclfnlc, a.I0.276 b.13.480 a"4.7714 B-105"01' the universal stage. Refractive indices .were de. Fom masured calculated termined by the ilnmersion method on crystals lying on (010) and (201) faces in sodium light. ,010 359"40, 89.55, 0"00' 90.00' 4 100 89010, 90.18, 90.00, 90"00' Pleochroism is weak, but was easily observed n ll0 54.19' 90.04, 53.38, 90'00' d zo1 -90"30' 34"22,-90.00' 3q"44' on most grains lying on (010). The absorption o z2l -44"55, 44.12t -44"24' 44"M' is greatest for vibration direction Z, as it TABLE 6. IJIIIT.CELL DII.IENSIONS,OPTICAL AND PHYSICALCONSTAI'ITS FOR erythrite. Optical data and some physical prop- PARASYMPLESITE erties are listed in Table 2 together wtth data (1954) This study' Ito et aL. Fe3(As04)2.8H20 previously reported by Larsen (1921) and Wolfe (1940). in oJuela nine, l,lexlco KJuva, Japan The optical orientation is shown single crystal powderdata slnqlg crystal Figure 1b. a 10.30(2) 10.276(4) 10.254 b 13.45(2) 13.480(5) 13.48 c 4.78 (21 4.771(2t 4.71 X-ray crystallography I 104"45'(rs') t05.01,(3,)r03o50, 62/tu - C2ln 2 22 The X-ray powder diffraction pattern of

4€as 3.12g/od 3.07 q/cm3 kiittigite is similar to those of the vivianite D""1 3.13 g,/cnr 2.r97-g/cn3 group. program of et al. Hardneii'" 2 The computer Evans (1963) was used to refine the unit-cell dimen- 4, 1.9?9\?l 1.628 ,B .:. 9:9 l.lI 1.660 sions given in Table 2. The data from the ^ ..4Y. r.065(r,l 1.705 upllc slgn posltlve powder diffraction pattern (Iable 3) are in 2y" reas. 860 (l) l"o't agreement gtoup ptoposed 2ip calc. 85' with the space C2/ m Disperslon trt by Wolfe (1940). Pleochroism yeak weai( .{ pale blue ,{ blulsh green I colorless r yellovish Chemical composition z color'less i bmmlsh ycllow libsorption x>r = Z orientatlonof X=b Dr. G. Springer of the Metallurgical Labora- the lndlcatrix z\c = + 29" (1J z^c = 31"24' tories, Falconbridge Nickel Mines Ltd., kindly For (Fe]. 68znl.32)r*3(Asoa)..8H.0 agreed to do a microprobe analysis of the

l't--t-

J-----L--r-

Fro. 2. (a) The common shape of paraslmplesite crystals from Ojuela mine, Mexico; (b) the orie,ntation of the optical and crystallographic elemeutsfor parasym.plesitecrystals lying on {010}. 444 THE CANADIAN MINERALOGIST

Schneeberg ktittigite. The result is compared blue streak The {010} cleavageis perfect, and in Table 4 to that given in Palache et al. (L95I) crystals can be bent easily. Hardness is about and to the composition calculated for the same 2-3. T:he density determined with a Berman Zn:Ni:Co atomic ratio as determined with the microbalance is 3.12 g/cm3, which compares microprobe. well with D""r"=3.13 g/cms. The optical properties are listed in Table 6 PARASYIVTpLBSITE and are compared to those grven by Ito et al. Radiating sprays of light blue crystals of para- (L954). Indices of refiaction were determined symplesite up to 5x1x0.2 mm are present on by the immersion method, and the orientation of altered rock from the Ojuela mins, Mapirni, the principal vibration directions @igure 2b) Mexico (ROM specimen M 34013). A drawing and optic axial angle were determined on tle of a typical crystal is shown in Figure 2a Most universal stage. The crystals are pale blue to para$ymplesite crystals are elongate parallel to colorless under the microscope. Pleochroism is [001] and flattened on {010}. The following weak, with absorption being strongest for X. forms were observedwith the optical goniometer on two crystals: {010}, {100}, t110}, X-ray crystallography and Measured and calculated 17ot; {124. Powder diffraction data are given in Table 7. values of Q and p for these forms are given in pattern (1954) has Table 5. The reported by Ito et al. more lines because some are CuKB lines, and Physical and optical properties because some symplesite is present. All lines observed in this study are in agreement with The crystals are pale blue, with a very pale powder data for other minerals of tle vivianite

TABLE7. X-MY POI,JDERDIFFMCTION DATA FOR PARASYMPLESITE group, except for differences in the intensities of the strong lines. (iuva, Jap€ 0Juela mlne, Itrlexlco* Ito et az. oJuela mlne. l4exlco Kluva, Refined unit-cell dimensions (fable 6) were 1954 ,lapan calculated from the powder diffraction pattern rest dobs dcalc lest dobs est dobs dcalc &z lest dobs with the computer program of Evans et aJ. 't8 (1963). Single-crystalstudy with Weisenbergand 9.006 ''-"'a ,iE a.zva zza r2 8.119 2.202151 precession carneras gave the possible space 17 7.499 I 2.1072.'tO7 132 38 7.063 ?.0922.090 350 groups C2, Cm, C2/ m. Because the crystals 100 6.68 6.74 020 ]00 6.830 ?0 4.95 4.96 200 9 5.051 ; r.ioar.ioa sio bend easily, unit-cell values from the single- 5 4.s9 4.61 001 -t '10 'I1.961 40 4.4074.410 lll q.izs .925 crystal study are inferior to those calculated 5 4.0924.093 130 B 4.051 I 1.914 from the powder pattern. | 3.992 3.996 220 9 3.991 't05 r.847 '1530 3.9143.921 Zol 1.694 I 1.694 3.67s3.675 11 1 10 3.723 I r.690 9 3.423 I 1.688 r0 3.395 r.673 Chemical composition l3r l0 3.250 'I 310 'I 1.627 D. R. Owens, Mineralogy Section, CANMET, io l.izz 'I1.620 zil 9 3.038 5 .610 Ottawa, kindly performed a microprobe analysis 3r'r l5 ,.yu l0'I r.549 of parasymplesite (Table 8). The Zn/Fe ratio zn 1.538 221 1.521 varies slightly from spot to spot over the sur- 041 z.Zg'. 20'I 'r1.507 Ni 330 .491 face of the crystals, indicating weak zoning. 241 z.itz 5 I .469 Co, Sb or P were not detected. Aor 2.496 '1.439 2.411 It is impossible to calculate the exact formula lir 'I1.422 'r.394 from the microprobe analysis, since the water ztz , it6 .367 values for 421 2.n6 t .552 content was not determined. The 060 2.264 1.271 ZnO and FeO probably representthe true Fe/7a 241 2.252 ratio in the crystals, and give an atomic ratio * Gllnler camra, Cu.trqmdlation, lntenslties esfimted vJsually of. I.27 for Fe/Zn so that the formula may be TABLE8. CHB4ICALColIP0SITIoN 0F PARASYITIPLESITE,oJUELA t'ttitE. written as The MEIICO @er.eZnr.or)>=g(AsOr)r'8II:O. calculated chemical composition for a mineral olcrcprcbe ldeal (Fe1. with this Fe/Zn ratio is given in Table 8. 62n1.32)r,,(ko4)2'8t|zo Zno 16.86 '17.84 Feo 18.98 20.55 CoNcr,ustoNs a20S 38.12 38.18 q9 n.d' 2?,43 The new data for kiittigite, determined on 100.00 the analyzed srystals from-'Sahneeberg:; Ger- . good atonlc ratJo Fe:Zn Fe:Zn" many, are in agreement with the results 1.69:1.32 t.6B:1.32 obtained by Wolfe (1940) from Schneeberg riittrcrrs AND PARASYMPLESITB 441 material which he analyzed with a blow-pipe kiittigite, and D. R Owensfor the microprobe aie probably attriburible anatfsis of paraslmplesitea Cynthia Peat test. Small differences "composition {I1. to minor variations i" prepared mirs uitl-tle Guinier camera, and Larsen (1921) obtained"fi"^i""foptical propefoesfor Mi.t geten Driver typed tle.manuscript' Spe' kiittigite on material *ni.h ** nof analyze{ cial thanks are due to Dr. J. A. Mandarino for uoa ii -uy be speculatedthat his data werl de- his help in the preparationof this manuscript. terminedon someqfts1 minslal. The blue crystals from the Ojuela ming RTFERENcES Mexico, are intermediate members in the para- rn., ArPleMeN, D. E. & HAND' series. For the crystals on EveNs, H. T. symplesite-kiittigite D. S. (1963): The leasf-sguaresrefine' the ratio wuirsR, the Royal Ontario Museum specimen, ment of crystal unit cells with powder, diffrac- between Fe and Zn varies slightly, but is clearly tion data by an automatic computer indexing on the parasymplesite side of the series. metlod. Ptogarn Abst, Amer. Cryst. Assoc. There are small but distinct differences in the Ann. Meet., Cambridge,Mass., 42-43. refractive indices and unit-cell dimensions Per-Acun,C., BnnuAN, H. & Fnouorr,, C. (1951): among ktittigite from Germany, parasymplesite The Systemof Mineralogy 2, 7th ed.' John Wiley from Japan, and parasymplesite from Mexico. & Sons, New York. The differences do not seem to be linearly re- Iro, T., MnIAto, H. & Seruner, K. (1954): Para- lated to changes in chemical composition. In' symplesite, a new mineral polymo4lhous with termediate members of the series should be symplesite.Proc. tap. Acad. 30,3t8-324. examined to establish the relationships among LenseN, E. S. (1921): Microscopic deterrnination chemical composition, optics, and crystallog- of the nonopaque minerals. U. J. GeoI. Surv, raphy. Bull.679. WoLrE, C. W. (1970): Classification of tle min- eralsof the type As(XO)z.nH2O,Amer. Mineral, AcrNowrnpcElvrENTs 40, 787-809. The author would like to thank Dr. G. Manuscript received' April 1976' emended lune Springer for the microprobe analysis of the 1976.