Anthony R. Kampf

Nomenclature of the apatite supergroup minerals

The apatite supergroup includes minerals with a generic chemical formula IX M12 VII M23( IV TO4)3 X( Z ¼ 2); chemically they can be phosphates, arsenates, vanadates, silicates, and sulphates. The maximum space group symmetry is P63/m, but several members of the supergroup have a lower symmetry due to cation ordering and deviations from the ideal topology, which may result in an increase of the number of the independent sites. The apatite supergroup can be formally divided into five groups, based on crystal-chemical arguments: apatite group, hedyphane group, belovite group, britholite group, and ellestadite group. The abundance of distinct ions which may be hosted at the key-sites (M ¼ Ca 2þ , Pb 2þ , Ba 2þ , Sr 2þ , Mn 2þ , Na þ , Ce 3þ , La 3þ ,Y 3þ , Bi 3þ ;T ¼ P 5þ , As 5þ ,V 5þ , Si 4þ ,S 6þ ,B 3þ ;X ¼ F � , (OH) � , Cl � ) result in a large number of compositions which may have the status of distinct mineral species. Naming of apatite supergroup minerals in the past has resulted in nomenclature inconsistencies and problems. Therefore, an ad hoc IMA-CNMNC Subcommittee was established with the aim of rationalizing the nomenclature within the apatite supergroup and making some order among existing and potentially new mineral species. In addition to general recommendations for the handling of chemical (EPMA) data and for the allocation of ions within the various sites, the main recommendations of this subcommittee are the following: 1. Nomenclature changes to existing minerals. The use of adjectival prefixes for anions is to be preferred instead of modified Levinson suffixes; accordingly, six minerals should be renamed as follows: apatite-(CaF) to fluorapatite, apatite-(CaOH) to hydroxylapatite, apatite-(CaCl) to chlorapatite, ellestadite-(F) to fluorellestadite, ellestadite-(OH) to hydroxylellestadite, phospho- hedyphane-(F) to fluorphosphohedyphane. For the apatite group species these changes return the names that have been used in thousands of scientific paper, treatises and museum catalogues over the last 150 years. The new mineral IMA 2008-009, approved without a name, is here named stronadelphite. Apatite-(SrOH) is renamed fluorstrophite. Deloneite-(Ce) is renamed deloneite. The new mineral IMA 2009-005 is approved with the name fluorbritholite-(Y).

Lead-tellurium oxysalts from Otto Mountain near Baker, California: I. Ottoite, Pb2TeO5, a new mineral with chains of tellurate octahedra

Abstract Ottoite, Pb2TeO5, is a new tellurate from Otto Mountain near Baker, California. Most of the mining on Otto Mountain occurred between 1940 and 1970 and is attributed to Otto Fuetterer, for whom the mountain is now named. The new mineral occurs on fracture surfaces and in small vugs in brecciated quartz veins, which intersect granitic rocks. Ottoite is directly associated with acanthite, bromine-rich chlorargyrite, gold, iodargyrite, khinite, wulfenite, and four other new tellurates: housleyite, markcooperite, thorneite, and timroseite. Various other secondary minerals occur in the veins, including two other new secondary tellurium minerals, paratimroseite and telluroperite. Ottoite and most other secondary minerals of the quartz veins are interpreted as having formed from the partial oxidation of primary sulfides and tellurides during or following brecciation of the veins. A later generation of quartz mineralization then recemented the breccias, effectively isolating and protecting the secondary mineralization from further alteration. Ottoite is monoclinic, space group I2/a, with the unit cell: a = 7.5353(6), b = 5.7142(5), c = 10.8981(12) Å, β = 91.330(6)°, V = 469.13(8) Å3, and Z = 4. The mineral occurs as complex spear-shaped crystals in subparallel to divergent intergrowths. It is yellow and transparent to translucent, with a pale yellow streak and adamantine luster. Mohs hardness is estimated at 3. The mineral is brittle, with an irregular fracture and two cleavages in the [100] zone at ~90°-possibly on {010} and {001}. The calculated density is 8.721 g/cm3. Ottoite is biaxial (-), with a large 2V, but indices of refraction are too high to be measured. The optic orientation could only partially be determined: Y ≈ a. No pleochroism was observed. Electron microprobe analyses provided the following averages: PbO 68.88 and TeO3 28.03, total 96.95 wt%; the empirical formula (based on O = 5) is Pb1.96Te6+1.01O5. The strongest powder X-ray diffraction lines are [dobs in Å (hkl) I]: 3.131 (2̅02) 64, 3.055 (013) 90, 3.015 (211) 100, 2.112 (2̅22) 29, 1.810 (006, 2̅15) 21, 1.773 (4̅11, 402) 43, 1.686 (033, 231) 20. The crystal structure (R1 = 0.020) consists of straight chains of trans-corner-sharing Te6+O6 octahedra parallel to a, which are joined by bonds to Pb atoms. The Pb atom exhibit markedly lopsided 11-coordination, typical of Pb2+ with stereoactive 6s2 lone-pair electrons. The powder X-ray diffraction pattern of ottoite is very similar to that reported for girdite. Examination of girdite type material suggests that its description was based upon data obtained from at least two and possibly three different phases, one of which may correspond to ottoite.

Krotite, CaAl2O4, a new refractory mineral from the NWA 1934 meteorite

Abstract Krotite, CaAl2O4, occurs as the dominant phase in an unusual Ca-,Al-rich refractory inclusion from the NWA 1934 CV3 carbonaceous chondrite. Krotite occupies the central and mantle portions of the inclusion along with minor perovskite, gehlenite, hercynite, and Cl-bearing mayenite, and trace hexamolybdenum. A layered rim surrounds the krotite-bearing regions, consisting from inside to outside of grossite, mixed hibonite, and spinel, then gehlenite with an outermost layer composed of Al-rich diopside. Krotite was identified by XRD, SEM-EBSD, micro-Raman, and electron microprobe. The mean chemical composition determined by electron microprobe analysis of krotite is (wt%) Al2O3 63.50, CaO 35.73, sum 99.23, with an empirical formula calculated on the basis of 4 O atoms of Ca1.02Al1.99O4. Single-crystal XRD reveals that krotite is monoclinic, P21/n; a = 8.6996(3), b = 8.0994(3), c = 15.217(1) Å, β = 90.188(6), and Z = 12. It has a stuffed tridymite structure, which was refined from single-crystal data to R1 = 0.0161 for 1014 Fo > 4σF reflections. Krotite is colorless and transparent with a vitreous luster and white streak. Mohs hardness is ~6½. The mineral is brittle, with a conchoidal fracture. The calculated density is 2.94 g/cm3. Krotite is biaxial (-), α = 1.608(2), β = 1.629(2), γ = 1.635(2) (white light), 2Vmeas = 54.4(5)°, and 2Vcalc = 55.6°. No dispersion was observed. The optical orientation is X = b; Y ≈ a; Z ≈ c. Pleochroism is colorless to very pale gray, X > Y = Z. Krotite is a low-pressure CaAl2O4 mineral, likely formed by condensation or crystallization from a melt in the solar nebula. This is the first reported occurrence of krotite in nature and it is one of the earliest minerals formed in the solar system.

Phosphohedyphane, Ca2Pb3(PO4)3Cl, the phosphate analog of hedyphane: Description and crystal structure

Abstract Phosphohedyphane, Ca2Pb3(PO4)3Cl, space group P63/m, a = 9.857(1), c = 7.130(2) Å, V = 599.9(2) Å3, Z = 2, is a new mineral from the Capitana mine, Copiapó, Atacama Province, Chile and has been identified from numerous other deposits world-wide. At the Capitana mine, it occurs as transparent, colorless, tapering hexagonal prisms, as individuals up to about 0.5 mm in length and 0.1 mm in diameter, which are commonly doubly terminated. Crystals often occur in subparallel intergrowths and irregular clusters. Phosphohedyphane forms as a secondary mineral in the oxidized zone of the Capitana mine, a Cu-Pb-Ag deposit, where it closely associated with quartz, duftite, and bayldonite. Crystals exhibit core-to-rim chemical zonation and electron analyses of cores/rims yielded CaO 9.24/7.76, PbO 67.60/69.35, P2O5 18.40/17.00, As2O5 2.73/3.68, Cl 3.32/3.22, .O = Cl .0.75/.0.73, total 100.54/100.28 wt%. The name phosphohedyphane is for the relationship of the mineral to hedyphane. The mineral has an apatite structure with ordering of Ca and Pb in the two non-equivalent large cation sites, as in hedyphane. The structure refinement indicates that the Ca2(6h) site is completely occupied by Pb and the Ca1(4f) site is occupied by 92% Ca and 8% Pb. The tetrahedral site refines to 91% P and 9% As. The refinement indicates the 0,0,0 position to be fully occupied by Cl. The ordering of Ca and Pb in phosphohedyphane has important implications with respect to the chlorapatite-pyromorphite solid solution series. An analysis of compositions of natural members of the pyromorphite-mimetite-turneaureite-chlorapatite system suggests the existence of complete solid solution among pyromorphite, mimetite, hedyphane, and phosphohedyphane. No stable solid solutions appear to exist between the joins phosphohedyphane-hedyphane and chlorapatite-turneaureite in natural systems.

Lead-tellurium oxysalts from Otto Mountain near Baker, California: IV. Markcooperite, Pb(UO2)Te6+O6, the first natural uranyl tellurate

Abstract Markcooperite, Pb2(UO2)Te6+O6, is a new tellurate from Otto Mountain near Baker, California, named in honor of Mark A. Cooper of the University of Manitoba for his contributions to mineralogy. The new mineral occurs on fracture surfaces and in small vugs in brecciated quartz veins. Markcooperite is directly associated with bromian chlorargyrite, iodargyrite, khinite-4O, wulfenite, and four other new tellurates: housleyite, thorneite, ottoite, and timroseite. Various other secondary minerals occur in the veins, including two other new secondary tellurium minerals: paratimroseite and telluroperite. Markcooperite is monoclinic, space group P21/c, a = 5.722(2), b = 7.7478(2), c = 7.889(2) Å, β = 90.833(5)°, V = 349.7(2) Å3, and Z = 2. It occurs as pseudotetragonal prisms to 0.2 mm with the forms {100} and {011} and as botryoidal intergrowths to 0.3 mm in diameter; no twinning was observed. Markcooperite is orange and transparent, with a light orange streak and adamantine luster, and is non-fluorescent. Mohs hardness is estimated at 3. The mineral is brittle, with an irregular fracture and perfect {100} cleavage. The calculated density is 8.496 g/cm3 based on the empirical formula. Markcooperite is biaxial (+), with indices of refraction α = 2.11, β = 2.12, γ = 2.29 calculated using the Gladstone-Dale relationship, measured α-β birefringence of 0.01 and measured 2V of 30(5)°. The optical orientation is X = c, Y = b, Z = a. The mineral is slightly pleochroic in shades of orange, with absorption: X > Y = Z. No dispersion was observed. Electron microprobe analysis provided PbO 50.07, TeO3 22.64, UO3 25.01, Cl 0.03, O≡Cl -0.01, total 97.74 wt%; the empirical formula (based on O+Cl = 8) is Pb2.05U0.80Te6+1.18O7.99Cl0.01. The strongest powder X-ray diffraction lines are [dobs in Å (hkl) I]: 3.235 (120, 102, 1̅02) 100, 2.873 (200) 40, 2.985 (1̅21, 112, 121) 37, 2.774 (022) 30, 3.501 (021, 012) 29, 2.220 (221, 2̅21, 212) 23, 1.990 (222, 2̅22) 21, and 1.715 (320) 22. The crystal structure (R1 = 0.052) is based on sheets of corner-sharing uranyl square bipyramids and tellurate octahedra, with Pb atoms between the sheets. Markcooperite is the first compound to show Te6+ substitution for U6+ within the same crystallographic site. Markcooperite is structurally related to synthetic Pb(UO2)O2.

Lead-tellurium oxysalts from Otto Mountain near Baker, California: II. Housleyite, Pb6CuTe4O18(OH)2, a new mineral with Cu-Te octahedral sheets

Abstract Housleyite, Pb6CuTe4O18(OH)2, is a new tellurate from Otto Mountain near Baker, California, named in honor of Robert M. Housley. The new mineral occurs on fracture surfaces and in small vugs in brecciated quartz veins. Housleyite is directly associated with acanthite, cerussite, gold, iodargyrite, khinite-4O, wulfenite, and three other new tellurates: markcooperite, ottoite, and thorneite. A variety of other secondary minerals occur in the veins, including three other new secondary tellurium minerals, paratimroseite, telluroperite, and timroseite. Housleyite is monoclinic, space group P21/n, a = 7.8552(5), b = 10.4836(7), c = 11.0426(8) Å, β = 95.547(2)°, and Z = 2. Crystals are prismatic to bladed with elongation parallel to b and typically occur in bow tie-like aggregates, drusy balls, and irregular sprays. It is pale to medium greenish blue and transparent, with pale blue streak and adamantine luster. Mohs hardness is estimated at 3. The mineral is brittle, with an irregular fracture. Cleavage was not observed, but is likely on {101}. The calculated density is 7.845(1) g/cm3. Housleyite is biaxial (+), with 2V = 50° to 60° and strong inclined dispersion, r > v, but indices of refraction are too high to be measured. The optic orientation is Y = b, Z ^ c ≈ 40° in obtuse β and pleochroism is Y (medium green-blue) > Z (light green-blue) > X. Energy dispersive spectroscopy provided PbO 62.53, CuO 3.77, TeO3 32.85, H2O 0.84 (structure), total 99.99 wt%.; the empirical formula (based on O = 20) is Pb5.99Cu1.01Te4.00O18(OH)2. The strongest powder X-ray diffraction lines are [dobs in Å (hkl) I]: 3.336 (2̅02, 031, 122) 69, 3.292 (1̅13) 50, 3.195 (130, 103) 100, 3.068 (2̅21, 202) 47, 3.007 (023) 49, 2.942 (032, 212) 80, 2.723 (123, 2̅13, 132) 29, 2.580 (230, 3̅01, 2̅31) 38. The crystal structure (R1 = 0.028) consists of corner-sharing chains of TeO6 octahedra along [101] linked into slabs parallel to {101̅} by sharing edges and corners with strongly Jahn-Teller (4+2) distorted and severely skewed CuO6 octahedra. Lead (Pb) atoms in lopsided nine- and elevenfold coordinations form additional links within and between the octahedral sheets.

The crystal structure of Ga-rich plumbogummite from Tsumeb, Namibia

Abstract Ga-rich plumbogummite, (Pb0.87,Ca0.13)Σ1.00H(Al1.95,Ga1.05)Σ3.00(PO4)2(OH)6, from Tsumeb, Namibia, has rhombohedral symmetry, space group R 3̅m, with the cell parameters a = 7.0752(19) Å, c = 16.818(4) Å and V = 729.1(3) Å3. The crystal structure has been refined to R1 = 2.05%. Ga-rich plumbogummite has an alunite-type structure comprised of a rhombohedral stacking of (001) composite layers of corner-shared (Al,Ga)O6 octahedra and PO4 tetrahedra, with Pb atoms occupying icosahedrally coordinated sites between the layers. The Pb and H positions are discussed. Ga-rich plumbogummite is nonpleochroic, uniaxial (+), with indices of refraction, ε = 1.742(3) and ω = 1.722(3), determined in white light. The five strongest powder-diffraction lines [d in Å, (I/Io), (hkl)] are: 2.995, (100), (113); 5.766, (95), (101); 2.236, (43), (107, 122); 3.539, (38), (110); 1.919 (32), (303, 033).

Lead-tellurium oxysalts from Otto Mountain near Baker, California: III. Thorneite, Pb6(Te26+O10)(CO3)Cl2(H2O), the first mineral with edge-sharing octahedral tellurate dimers

Abstract Thorneite, Pb6(Te26+O10)(CO3)Cl2(H2O), is a new tellurate from Otto Mountain near Baker, California, named in honor of Brent Thorne. The new mineral occurs on fracture surfaces and in small vugs in brecciated quartz veins. Thorneite is directly associated with acanthite, cerussite, gold, hessite, iodargyrite, khinite, wulfenite, and three other new tellurates: housleyite, markcooperite, and ottoite. Various other secondary minerals occur in the veins, including three other new secondary tellurium minerals: paratimroseite, telluroperite, and timroseite. Thorneite is monoclinic, space group C2/c, a = 21.305(1), b = 11.059(1), c = 7.564(1) Å, β = 101.112(4)°, V = 1748.8(4) Å3, and Z = 4. Crystals are prismatic to bladed with elongation and striations parallel to c and typically occur in parallel and random aggregates. It is yellow and transparent, with pale yellow streak and adamantine luster. Mohs hardness is estimated at 2. The mineral is brittle, with an irregular to splintery fracture and good {100} cleavage. The calculated density is 6.828 g/cm3. Thorneite is biaxial (+), with large 2V, but indices of refraction are too high to be measured. The optic orientation is Y = b, Z ^ a = 29° in obtuse β. No pleochroism was observed. Electron microprobe analysis provided PbO 73.90, ZnO 0.03, TeO3 20.35, Cl 2.29, H2O 1.28 (structure), CO2 2.29 (structure), O≡Cl -0.52, total 99.62 wt%; the empirical formula (based on O+Cl = 16) is (Pb5.94Zn0.01)(Te6+2.08O10)(C1.00O3)[Cl1.16O0.34(OH)0.50](H2O). The strongest powder X-ray diffraction lines are [dobs in Å (hkl) I]: 10.43 (200) 35, 3.733 (5̅11, 2̅02, 002) 27, 3.595 (4̅21) 33, 3.351 (112) 66, 3.224 (511, 131) 100, 3.093 (2̅22, 3̅31) 30, 2.900 (6̅21) 44, 2.133 (821, 622, 223, 731, 242) 38. The crystal structure (R1 = 0.028) contains edge-sharing octahedral tellurate dimers, [Te26+O10]8- that bond to Pb atoms, which in turn are linked via bonds to Cl atoms, CO3 triangles, and H2O molecules.

Lead-tellurium oxysalts from Otto Mountain near Baker, California: VI. Telluroperite, Pb3Te4+O4Cl2, the Te analog of perite and nadorite

Abstract Telluroperite, Pb3Te4+O4Cl2, is a new tellurite from Otto Mountain near Baker, California. The new mineral occurs on fracture surfaces and in small vugs in brecciated quartz veins in direct association with acanthite, bromine-rich chlorargyrite, caledonite, cerussite, galena, goethite, and linarite. Various other secondary minerals occur in the veins, including six new tellurates, housleyite, markcooperite, paratimroseite, ottoite, thorneite, and timroseite. Telluroperite is orthorhombic, space group Bmmb, a = 5.5649(6), b = 5.5565(6), c = 12.4750(14) Å, V = 386.37(7) Å3, and Z = 2. The new mineral occurs as rounded square tablets and flakes up to 0.25 mm on edge and 0.02 mm thick. The form {001} is prominent and is probably bounded by {100}, {010}, and {110}. It is bluish-green and transparent, with a pale bluish-green streak and adamantine luster. The mineral is non-fluorescent. Mohs hardness is estimated to be between 2 and 3. The mineral is brittle, with a curved fracture and perfect {001} cleavage. The calculated density based on the empirical formula is 7.323 g/cm3. Telluroperite is biaxial (-), with very small 2V (~10°). The average index of refraction is 2.219 calculated by the Gladstone-Dale relationship. The optical orientation is X = c and the mineral exhibits moderate bluish-green pleochrosim; absorption: X < Y = Z. Electron microprobe analysis provided PbO 72.70, TeO2 19.26, Cl 9.44, O≡Cl -2.31, total 99.27 wt%. The empirical formula (based on O+Cl = 6) is Pb2.79Te4+1.03O3.72Cl2.28. The six strongest powder X-ray diffraction lines are [dobs in Å (hkl) I]: 3.750 (111) 58, 2.857 (113) 100, 2.781 (020, 200) 43, 2.075 (024, 204) 31, 1.966 (220) 30, and 1.620 (117, 313, 133) 52. The crystal structure (R1 = 0.056) is based on the Sillén X1 structure-type and consists of a three-dimensional structural topology with lead-oxide halide polyhedra linked to tellurium/lead oxide groups. The mineral is named for the relationship to perite and the dominance of Te (with Pb) in the Bi site of perite.

The crystal chemistry and crystal structure of kuksite, Pb3Zn3Te6+P2O14, and a note on the crystal structure of yafsoanite, (Ca,Pb)3Zn(TeO6)2

Abstract New discoveries of kuksite, Pb3Zn3Te6+P2O14, from the Black Pine mine, Montana, and Blue Bell claims, California, have enabled a detailed crystal-chemical study of the mineral to be undertaken. Single-crystal X-ray structure refinements of the structure indicate that it is isostructural with dugganite, Pb3Zn3Te6+As2O14, and joëlbruggerite, Pb3Zn3(Sb5+,Te6+)As2O13(OH,O). Kuksite from the Black Pine mine crystallizes in space group P321, with unit-cell dimensions a = 8.392(1), c = 5.204(1) Å, V = 317.39(8) Å3, and Z = 1 (R1 = 2.91% for 588 reflections [Fo > 4σF] and 3.27% for all 624 reflections), while Blue Bell kuksite has the unit cell a = 8.3942(5), c = 5.1847(4) Å, and V = 316.38(4) Å3 (R1 = 3.33% for 443 reflections [Fo > 4σF] and 3.73% for all 483 reflections). Chemical analyses indicate that solid-solution series exist between kuksite, dugganite, and joëlbruggerite. Raman spectroscopic and powder X-ray diffraction data are also presented for samples from both occurrences. The crystal structure of the chemically related species yafsoanite, (Ca,Pb)3Te26+Zn3O12, from the type locality (Delbe orebody, Kuranakh Au Deposit, Aldan Shield, Saha Republic, Russia), has been refined to R1 = 2.41% for 135 reflections [Fo > 4σF] and 3.68% for all 193 reflections. A garnet-type structure has been confirmed and significantly improves upon the results of an earlier structure determination