Phosphates of the Chalotskoe pegmatite deposit (Transbaikalia)

Lykova I. S., Varlamov D. A., Chukanov N. V., Pautov L. A., Ksenofontov D. A.

Zapiski RMO (Proceedings of the Russian Mineralogical Society). 2017. V. 146. N 4. P. 44-53

Full text is available on eLIBRARY.RU

Language: Russian

Abstract

A scope of rare phosphates have been found in specimens from Chalotskoe pegmatite deposit (Transbaikalia): väyrynenite, MnBe[PO4](OH,F); parascholzite, CaZn2[PO4]2 2H2O; messelite, Ca2(Fe2+,Mn)[PO4]22H2O; eosphorite, MnAl[PO4](OH)2H2O; moraesite, Be2[PO4](OH)4H2O, as well as fluorapatite. Väyrynenite forms pink grains 2—3 mm in size, more rarely prismatic crystals up to 0.8  3.0 cm, and spherulites up to 3 mm in diameter. Parascholzite occurs as nests up to 0.6  1.0 cm composed from snow-white small grains. Messelite is represented by pale yellow honeycomb grains and poorly shaped crystals up to 1 mm. Eosphorite was known in pegmatites of the Chalotskoe deposit before, but it was not explicitly studied there. It occurs in red-brown prismatic crystals up to 8 cm in length, occasionally forming open-book-like aggregates and pink to pale pink grains size up to 5 mm. Moraesite composes snow-white fibrous aggregates up to 5  6 mm, together with white spherulites and short-prismatic crystals of fluorapatite up to 1 mm. Associated minerals are microcline, albite, quartz, muscovite, beryl, schorl, almandine-spessartine, columbite-(Fe), and bertrandite. Finds of väyrynenite and parascholzite are for the first time reported in Russia.

Key words: väyrynenite, parascholzite, messelite, eosphorite, moraesite, phosphate minerals, granitic pegmatite, Chalotskoe deposit, Transbaikalia.