Mineral Species: Volkonskoite and Corundum var. Ruby
Chemical Formula: Ca0:3(Cr3+;Mg;Fe3+)2(Si;Al)4O10(OH)2 ²4H2O
Chemical Name: Chromium Magnesium Iron Silicate Hydroxide
Mineral Class: Phyllosilicate
Mineral Notes: Volkonskoite is an epigenetic mineral in sandstones, conglomerates, and red beds, commonly filling voids from the decomposition of organic matter (Okhansk region, Russia) or a weathering product of serpentinite (Gotse Delchev, Bulgaria). The mineral belongs to the Smectite group. It was named after Prince Petr Mikhailovich Volkonskii (1776 - 1852), Minister of the Imperial Court, Russia, patron of the natural sciences.
Description: Hundreds of Corundum crystals embedded in schist matrix, The colour is deep cherry-red and there are bright reflections from crystal faces. Many show stepped, triangular terminations. The largest crystals show some transparency. The Volkonskoite appears as pale green streaks scattered over the surface of the matrix, between several of the Ruby crystals.
Location: Kleggåsen Ruby Quarry, Froland, Aust-Agder, Norway.
