Cinnabar on Dolomite

Several small purplish red rhombohedral, euhedral Cinnabar crystals entwined with white rhombohedral, subhedral Dolomite crystals. Cinnabar crystals have a dull lustre and a vitreous lustre for the Dolomite crystals. Cinnabar crystal size: 0.7 cm x 0.3 cm x 0.2 cm. Average Dolomite crystal size: 0.4 cm x 0.3 cm x 0.1 cm. Cinnabar (HgS) can be bright-red, purplish red to brownish red in colour and it has an adamantine or dull lustre. Streak is scarlet red to brownish red and hardness is 2 to 2 1/2. Cleavage is perfect in three direction at 60 degrees and 120 degrees. Cinnabar usually occurs as rhombohedral and thick tabular crystals but can also granular, earthy or incrusting. Dolomite (CaMg(CO3)2) can be white, pink, grey, green, brown, black or colourless with a vitreous or pearly lustre. Streak is white and hardness is 3 1/2 to 4. Cleavage is perfect in three directions. Dolomite tends to occur as rhombohedral crystals with curved faces but can also be granular, massive (Dolomite Rock) compact or cleavable masses.