A new mineral species, named naquite（FeSi）, is found in the podiform chromitites of the Luobusha ophiolite in Qusong County, Tibet, China. The detailed composition is Fe 65.65, Si 32.57 and Al 1.78 wt%. The mineral ...A new mineral species, named naquite（FeSi）, is found in the podiform chromitites of the Luobusha ophiolite in Qusong County, Tibet, China. The detailed composition is Fe 65.65, Si 32.57 and Al 1.78 wt%. The mineral is cubic, space group P213. The irregular crystals range from 15 to 50 μm in diameter and form an intergrowth with luobusaite. Naquite is steel grey in color, opaque, with a metallic lustre and gives a grayish-black streak. The mineral is brittle, has a conchoidal fracture and no apparent cleavage. The estimated Mohs hardness is 6.5, and the calculated density is 6.128 g/cm3. Unit-cell parameters are a 4.486 （4） A, V 90.28 （6）A^3, Z=4. The five strongest powder diffraction lines [d inA（hkl） （I/I0）] are： 3.1742 （110） （40）, 2.5917（111） （43）, 2.0076 （210） （100）, 1.8307 （211） （65）, and 1.1990 （321） （36）. Originally called ＇fersilicite＇, the species and new name have now been approved by the CNMNC （IMA 2010-010）.展开更多
Hydroxycalciopyrochlore,ideally （Ca,Na,U,□）2（Nb,Ti）2O6（OH）,cubic,is a new mineral species （IMA2011-026） within the pyrochlore supergroup that was found occurring at the Maoniuping mine,Mianning County,Xichang...Hydroxycalciopyrochlore,ideally （Ca,Na,U,□）2（Nb,Ti）2O6（OH）,cubic,is a new mineral species （IMA2011-026） within the pyrochlore supergroup that was found occurring at the Maoniuping mine,Mianning County,Xichang prefecture,Sichuan Province,southwest China.The mineral is found in an alkali feldspar granite rare-earth ore deposit （26-27 Ma）.Associated minerals include calcite,barite,celestine,albite,aegirine,aegirine-augite,fluorite,parasite-（Ce）,thorite,thorianite,zircon,galena,sphalerite,magnetite,and pyrite.Crystals occur mostly as octahedra,and less often as dodecahedra and tetrahexahedra or combinations thereof.Some occur with an allotriomorphic habit with a thick triangular tabular form.Crystals generally range from 0.1 to 1 mm in size.The mineral is brownishblack,greenish-black and black on fresh sections with a brown streak.The crystal is translucent,and has a greasy lustre on fresh sections.It is metamict without any observed parting or cleavage and with a conchoidal fracture.The Vickers microhardness is 572 kg/mm2 （5-6 on the Mohs hardness scale）.The density measured by hydrostatic weighing is 5.10（3） g/cm3.The strongest four reflections in the X-ray powder-diffraction pattern [d in（A） （Ⅰ） hkl] are：2.9657 （100） 2 2 2,1.8142 （34） 0 4 4,1.5463 （21） 2 2 6,2.5688 （18） 0 0 4.The unit-cell parameters are a =10.381（4） （A）,V=1118.7（7）（A）3,Z =8.The structure was solved and refined in the space group Fd3m with R =0.09.The empirical formula is （Ca0.74Na0.5sU0.40Ce0.05Fe0.02□0.21）2.00（Nb1.15Ti0.s0Ta0.03Al0.01Mg0.01）2.00O6.02 [（OH）1.01F0.09]1.10,on the basis of 2 atoms of B pfu; the simplified formula is （Ca,Na,U,□）2（Nb,Ti）2O6（OH）.Type material is deposited in the Geological Museum of China,Beijing,People＇s Republic of China,catalogue number M11800.展开更多
基金supported financially by the National Natural Science Foundation of China (Grant No. 40472025, 40620120098,40872043)
文摘A new mineral species, named naquite（FeSi）, is found in the podiform chromitites of the Luobusha ophiolite in Qusong County, Tibet, China. The detailed composition is Fe 65.65, Si 32.57 and Al 1.78 wt%. The mineral is cubic, space group P213. The irregular crystals range from 15 to 50 μm in diameter and form an intergrowth with luobusaite. Naquite is steel grey in color, opaque, with a metallic lustre and gives a grayish-black streak. The mineral is brittle, has a conchoidal fracture and no apparent cleavage. The estimated Mohs hardness is 6.5, and the calculated density is 6.128 g/cm3. Unit-cell parameters are a 4.486 （4） A, V 90.28 （6）A^3, Z=4. The five strongest powder diffraction lines [d inA（hkl） （I/I0）] are： 3.1742 （110） （40）, 2.5917（111） （43）, 2.0076 （210） （100）, 1.8307 （211） （65）, and 1.1990 （321） （36）. Originally called ＇fersilicite＇, the species and new name have now been approved by the CNMNC （IMA 2010-010）.
基金supported by the National Natural Science Foundation of China (grant #41172052)
文摘Hydroxycalciopyrochlore,ideally （Ca,Na,U,□）2（Nb,Ti）2O6（OH）,cubic,is a new mineral species （IMA2011-026） within the pyrochlore supergroup that was found occurring at the Maoniuping mine,Mianning County,Xichang prefecture,Sichuan Province,southwest China.The mineral is found in an alkali feldspar granite rare-earth ore deposit （26-27 Ma）.Associated minerals include calcite,barite,celestine,albite,aegirine,aegirine-augite,fluorite,parasite-（Ce）,thorite,thorianite,zircon,galena,sphalerite,magnetite,and pyrite.Crystals occur mostly as octahedra,and less often as dodecahedra and tetrahexahedra or combinations thereof.Some occur with an allotriomorphic habit with a thick triangular tabular form.Crystals generally range from 0.1 to 1 mm in size.The mineral is brownishblack,greenish-black and black on fresh sections with a brown streak.The crystal is translucent,and has a greasy lustre on fresh sections.It is metamict without any observed parting or cleavage and with a conchoidal fracture.The Vickers microhardness is 572 kg/mm2 （5-6 on the Mohs hardness scale）.The density measured by hydrostatic weighing is 5.10（3） g/cm3.The strongest four reflections in the X-ray powder-diffraction pattern [d in（A） （Ⅰ） hkl] are：2.9657 （100） 2 2 2,1.8142 （34） 0 4 4,1.5463 （21） 2 2 6,2.5688 （18） 0 0 4.The unit-cell parameters are a =10.381（4） （A）,V=1118.7（7）（A）3,Z =8.The structure was solved and refined in the space group Fd3m with R =0.09.The empirical formula is （Ca0.74Na0.5sU0.40Ce0.05Fe0.02□0.21）2.00（Nb1.15Ti0.s0Ta0.03Al0.01Mg0.01）2.00O6.02 [（OH）1.01F0.09]1.10,on the basis of 2 atoms of B pfu; the simplified formula is （Ca,Na,U,□）2（Nb,Ti）2O6（OH）.Type material is deposited in the Geological Museum of China,Beijing,People＇s Republic of China,catalogue number M11800.
