Original paper
Tetrarooseveltite, ß-Bi(AsO4), a new mineral species from Moldava deposit, the Krusné hory Mts., Northwestern Bohemia, Czech Republic
Sejkora, J.; Řídkošil, T.
Neues Jahrbuch für Mineralogie - Monatshefte Jg. 1994 Heft 4 (1994), p. 179 - 184
17 references
published: Apr 8, 1994
DOI: 10.1127/njmm/1994/1994/179
ArtNo. ESP156199404005, Price: 19.00 €
Abstract
Tetrarooseveltite, ß-Bi (AsO4), is tetragonal, space group I 41/a, with a 5.085(5)Å, c 11.69 (1)Å, V 303.3Å 3, Z = 4 and Dcalc. = 7.64g/cm3. The strongest lines in the X-ray powder diffraction pattern are (d in Å, I, hkl) 4.66(11)(101), 3.066(100)(112), 2.546(12)(200), 1.797(11)(220), 1.581(10)(107), 1.551(17)(312). Tetrarooseveltite is isostructural with scheelite and dimorphous with rooseveltite. Tetrarooseveltite forms fine grained powder aggregates with hardness about 2.5, it has an earthy luster, white to yellowish-white colour and is non fluorescent. The mineral is uniaxial positive with mean index of refraction Nm = 2.20(5) for Na light. Microprobe analyses yield an average composition of Bi203 66.96, As2O533.02, P2O5 0.03, total 100.01 wt. % leading to a formula BiAsO4. The mineral has been found as an oxidation product Bi-Ag-As-Co-Ni containing fluorite-barite-quartz vein Josef at Moldava deposit, the Krušné Hory Mts., Northwestern Bohemia, Czech Republic.
Keywords
Tetrarooseveltite • new mineral species • bismuth arsenate • Moldava • Czech Republic