CINNABAR (CINNABARITE or MERCURBLENDE) on CALCITE, HUNAN TIEN MINE, PRC SMALL CABINET

Cinnabar, also referred to as cinnabarite or mercurblende, is a vivid scarlet to brick-red variant of mercury(II) sulfide (HgS). It serves as the primary ore for extracting elemental mercury and has historically been the source of the striking red pigment known as vermilion, along with other red mercury-based pigments. 

This mineral typically forms in veins linked to volcanic activity and alkaline hot springs, displaying symmetry similar to quartz and showing birefringence. Cinnabar has an average refractive index of about 3.2, a hardness rating between 2.0 and 2.5, and a specific gravity around 8.1. Its distinctive color and characteristics arise from its hexagonal crystalline structure, which belongs to the trigonal crystal system, with some crystals exhibiting twinning.