BUSHMAKINITE Pb_2Al(PO_4)(VO_4)(OH), A NEW MINERAL OF THE BRACKEBUSCHITE GROUP FROM OXIDIZED ZONE OF BEREZOVSKOYE GOLD DEPOSIT, THE MIDDLE URALS

摘要

Bushmakinite, a new mineral of the brackebuschite group, has been discovered in a specimen from Berezovskoye gold deposit, Middle Urals, Russia. In occurs n assemblage formed by oxidation of nest consisting of galena and fahl ore in quart vein; associates with cerussite, bindheimite, vauquelinite, mottramite, pyromorphite. It forms lamellar crystals up to 0.3X0.2X0.02 mm. Translucent, bright-yellow, streak yellowish, luster vitreous. Brittle, cleavage perfect on (001). Mohs' hardness 3-3.5. D_(calc)=6.21 g/cm~3. Optically biaxial, negative; alpha=1.99, beta=2.03; gamma=2.06; 2V_(calc)=80 deg; dispersion of optical axes is significant, r