Rus
 

Stone, minerals and semiprecious of the world stone
Mica, isinglass stone (silicates): Lepidolite -->rus

   Diagnostic cart.

   K Li2 Al (F, OH)2 Si4O10
   Crystal structure monoclinic
   Hardness on the Mohs scale 2,5-3
   Specific unit weight mass 2,8-3
   Cleavage perfect absolute
   Fracture, break rough
   Colors pink, rose, purple
   Colors in powder triturate white
   Glance (glitter, glare) mother-of-pear nacreous

   A lepidolite (lithium mica) is aluminum silicate. Glance (glitter, glare) mother-of-pear nacreous. Opaque. Colors: rose, tints lilac to colourless. A line is white. Cleavage very perfect absolute. Leaves are flexible. Appears in pegmatites and changed granites. Presented mainly the aggregates of shallow scales. Lithium ore. Deposit minefield mine field occurrence subsoil is known on the south of Africa, USA.

   Now and then individual plate tablet lamellar forms pseudohexagonal crystals, more frequent are small on sizes aggregates of scales. It can be colourless, sometimes light-grey, rose and violet in-bulk. Has perfect cleavage along bottom base and glassy brilliance. A lilac, pink, or greyish mica consisting of a hydrous silicate of lithium, potassium, aluminium, and fluorine, containing rubidium as an impurity: a source of lithium and rubidium. Formula: K2Li3Al4Si7O21(OH,F)3.

   Diagnostic indication.

   A lepidolite is added the action of acids, but at the certain chart of treatment. On flame of candle melt fuse easily, painting flame in bright-pink, rose color, that is conditioned the presence of lithium.

   Origin provenance genesis.

   A lepidolite is the mineral of pegmatite-pneumatolysis origin, characteristic for granit pegmatites in which widespread together with quartz, tourmaline, topaz, tinstone, beryl and minerals of lithium.

   Deposit minefield mine and use.

   A mineral is met in Kulgardi in Western Australia, in Moravii (Czekh), on Ural, in Fallen in the state of Californium, in Pe-ning in Saxony (Germany), in alkaline pegmatites of Antsirabe on Madagascar and in granites on an island Elba (Italy). A lepidolite is ores on lithium, very easy metal, in-use in metallurgy. Salts of lithium are used in pharmaceutical industry, production of glass, lubricating materials.


Lepidolite. Sferokristally ("Barbotov of eyes"). Ak-kezen', . Kalba, Vost. Kazakhstan. A photo: © A.A. Evseev.


Lepidolite. Muyane -, Altu-ligon'ya, province Zambezi, Mozambique. A photo: © A.A. Evseev.