Entity

Time filter

Source Type

Salt Lake City, UT, United States

Kampf A.R.,Natural History Museum of Los Angeles County | Mararty J.,3457 E. Silver Oak Road | Thorne B.,3898 S. Newport Circle
American Mineralogist | Year: 2010

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, bβ = 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, H3O 0.84 (structure), total 99.99 wt%.; the empirical formula (based on O = 20) is b5.99Cu1.01Te4.00O 18(OH)2. The strongest powder X-ray diffraction lines are [dobs in Å (hkl) I]: 3.336 (202, 031, 122) 69, 3.292 (113) 50, 3.195 (130, 103) 100, 3.068 (221, 202) 47, 3.007 (023) 49, 2.942 (032, 212) 80, 2.723 (123, 213, 132) 29, 2.580 (230, 301, 231) 38. The crystal structure (R1 = 0.028) consists of corner-sharing chains of TeO6 octahedra along [101] linked into slabs parallel to {101} by sharing edges and corners with strongly Jahn-Teller (4+2) distorted and severely skewed CuO 6 octahedra. Lead (Pb) atoms in lopsided nine- and elevenfold coordinations form additional links within and between the octahedral sheets.


Kampf A.R.,Natural History Museum of Los Angeles County | Housley R.M.,California Institute of Technology | Mararty J.,3457 E. Silver Oak Road
American Mineralogist | Year: 2010

Thorneite, Pb6(Te2 6+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 (Pb5.94Zn 0.01)(Te6+ 2.08O10)(C 1.00O3)[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 (511, 202, 002) 27, 3.595 (421) 33, 3.351 (112) 66, 3.224 (511, 131) 100, 3.093 (222, 331) 30, 2.900 (621) 44, 2.133 (821, 622, 223, 731, 242) 38. The crystal structure (R1 = 0.028) contains edge-sharing octahedral tellurate dimers, [Te2 6+O10]8- that bond to Pb atoms, which in turn are linked via bonds to Cl atoms, CO3 triangles, and H2O molecules.


Kampf A.R.,Natural History Museum of Los Angeles County | Mills S.J.,University of British Columbia | Housley R.M.,California Institute of Technology | Mararty J.,3457 E. Silver Oak Road | Thorne B.,3898 S. Newport Circle
American Mineralogist | Year: 2010

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 a = 2.11, β = 2.12, ? = 2.29 calculated using the Gladstone-Dale relationship, measured a-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, 102) 100, 2.873 (200) 40, 2.985 (121, 112, 121) 37, 2.774 (022) 30, 3.501 (021, 012) 29, 2.220 (221, 221, 212) 23, 1.990 (222, 222) 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.


Kampf A.R.,Natural History Museum of Los Angeles County | Mills S.J.,University of British Columbia | Housley R.M.,California Institute of Technology | Mararty J.,3457 E. Silver Oak Road | Thorne B.,3898 S. Newport Circle
American Mineralogist | Year: 2010

Timroseite, Pb2Cu52+(Te6+O 6)2(OH)2, and paratimroseite, Pb 2Cu4 2+(Te6+O6) 2(H2O)2, are two new tellurates from Otto Mountain near Baker, California. Timroseite is named in honor of Timothy (Tim) P. Rose and paratimroseite is named for its relationship to timroseite. Both new minerals occur on fracture surfaces and in small vugs in brecciated quartz veins. Timroseite is directly associated with acanthite, cerussite, bromine-rich chlorargyrite, chrysocolla, gold, housleyite, iodargyrite, khinite-4O, markcooperite, ottoite, paratimroseite, thorneite, vauquelinite, and wulfenite. Paratimroseite is directly associated with calcite, cerussite, housleyite, khinite-4O, markcooperite, and timroseite. Timroseite is orthorhombic, space group P21nm, a = 5.2000(2), b = 9.6225(4), c = 11.5340(5) Å, V = 577.13(4) Å3, and Z = 2. Paratimroseite is orthorhombic, space group P212121, a = 5.1943(4), b = 9.6198(10), c = 11.6746(11) Å, V = 583.35(9) Å3, and Z = 2. Timroseite commonly occurs as olive to lime green, irregular, rounded masses and rarely in crystals as dark olive green, equant rhombs, and diamond-shaped plates in subparallel sheaf-like aggregates. It has a very pale yellowish green streak, dull to adamantine luster, a hardness of about 2= (Mohs), brittle tenacity, irregular fracture, no cleavage, and a calculated density of 6.981 g/cm3. Paratimroseite occurs as vibrant "neon" green blades typically intergrown in irregular clusters and as lime green botryoids. It has a very pale green streak, dull to adamantine luster, a hardness of about 3 (Mohs), brittle tenacity, irregular fracture, good {001} cleavage, and a calculated density of 6.556 g/cm3. Timroseite is biaxial (+) with a large 2V, indices of refraction < 2, orientation X = b, Y = a, Z = c and pleochroism: X = greenish yellow, Y = yellowish green, Z = dark green (Z < Y < X). Paratimroseite is biaxial (-) with a large 2V, indices of refraction < 2, orientation X = c, Y = b, Z = a and pleochroism: X = light green, Y = green, Z = green (Y = Z >> X). Electron microprobe analysis of timroseite provided PbO 35.85, CuO 29.57, TeO3 27.75, Cl 0.04, H2O 1.38 (structure), O=Cl -0.01, total 94.58 wt%; the empirical formula (based on O+Cl = 14) is Pb2.07 Cu2+ 4.80Te 6+ 2.04O12(OH)1.98Cl0.02. Electron microprobe analysis of paratimroseite provided PbO 36.11, CuO 26.27, TeO3 29.80, Cl 0.04, H2O 3.01 (structure), O=Cl -0.01, total 95.22 wt%; the empirical formula (based on O+Cl = 14) is Pb 1.94Cu2+ 3.96Te6+ 2.03O12(H2O)1.99Cl0.01. The strongest powder X-ray diffraction lines for timroseite are [dobs in Å (hkl) I]: 3.693 (022) 43, 3.578 (112) 44, 3.008 (023) 84, 2.950 (113) 88, 2.732 (130) 100, 1.785 (multiple) 33, 1.475 (332) 36; and for paratimroseite 4.771 (101) 76, 4.463 (021) 32, 3.544 (120) 44, 3.029 (023,122) 100, 2.973 (113) 48, 2.665 (131) 41, 2.469 (114) 40, 2.246 (221) 34. The crystal structures of timroseite (R1 = 0.029) and paratimroseite (R1 = 0.039) are very closely related. The structures are based upon edge- and corner-sharing sheets of Te and Cu polyhedra parallel to (001) and the sheets in both structures are identical in topology and virtually identical in geometry. In timroseite, the sheets are joined to one another along c by sharing the apical O atoms of Cu octahedra, as well as by sharing edges and corners with an additional CuO5 square pyramid located between the sheets. The sheets in paratimroseite are joined only via Pb-O and H bonds.


Kampf A.R.,Natural History Museum of Los Angeles County | Mills S.J.,University of British Columbia | Housley R.M.,California Institute of Technology | Mararty J.,3457 E. Silver Oak Road | Thorne B.,3898 S. Newport Circle
American Mineralogist | Year: 2010

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.

Discover hidden collaborations