American Mineralogist · 1980 · 22 citations · 1 references
Natural SciencesEarth SciencesGeologyCrystal StructureGeochemistryMineralogyCarbonate MineralsCrystal ChemistryMineral ChemistryMineral GeochemistryOxide MineralsPhysical Properties Of MineralsApatite Crystal ChemistryApatite Group MineralsApatite MineralogyCrystal Chemistry Of Ore MineralsCrystal Structure Of ApatitePowder DiffractionPowder Diffraction AnalysisPowder X-ray Diffraction
Johnbaumite, ideally Car(AsOo)r(OH), is a new mineral from the Franklin mine in Franklin, Sussex County, New Jersey. It is hexagonal space group P6t/m or P6r with a:9.70 and c:6.934. The strongest lines in the X-ray powder diffraction pattern are: (d, I, hkl 2.895 l002ll;2.798 703N;2.820 70ll2;3.47 50 002;3.98 50lll;2.683 45 202. Chemical analysis by microprobe and ore-rce yielded CaO 43.5, FeO 0.2, MgO 0.1, P2Os 1.7, AsrO,52.2, F 0.2, Cl0.1, H2O 1.3, less O : Cl 0.1, sum : 99.2 percent. Johnbaumite is white to colorless with a vitreous luster. Cleavage is distinct on {100}. The density is 3.68 g/cm3 (meas.), 3.73 g/cm3 (calc.). Johnbaumite is uniaxial (-) with refractive indices ot : | .687 , e : I .684. It is found associated with yeatmanite, romeite, andradite, diopside, franklinite, and copper. Johnbaumite is the arsenate analogue of hydroxylapatite and the hydroxyl analog of svabite.
1