Cinnabar in Matrix
Cinnabar (Mercury(II) sulfide) · Mineral Specimen / Toxic Ore Mineral
Crystal System
Trigonal; typically occurs in massive, granular, or earthy forms as seen in the red patches here, though it can form rhombohedral or tabular crystals.
Mineral Group
Sulfides
Chemical Formula
HgS
Formation Process
Hydrothermal; forms at relatively low temperatures in shallow veins or near hot springs and volcanic activity.
About This Crystal
The specimen features patches of vibrant scarlet-to-brick red cinnabar embedded in a grey-to-buff colored rocky matrix. The red portions exhibit a dull to sub-adamantine luster and are opaque to translucent.
Physical Characteristics
Color: Cochineal-red to brownish red; Streak: Scarlet; Cleavage: Perfect in three directions (prismatic); Fracture: Subconchoidal to uneven; Specific Gravity: ~8.1 (very heavy); Fluorescence: None.
Optical Properties
Extremely high refractive index (n=2.905–3.256); very high birefringence; typically presents an adamantine luster when crystalline.
Hardness & Durability
Origin Region
Notable sources include Almaden (Spain), Huancavelica (Peru), Guizhou (China), and California (USA); found in volcanic and hydrothermal environments.
Hardness & Durability
Mohs hardness: 2.0 to 2.5 (very soft); Brittle; low durability. It can be scratched by a fingernail or a copper coin.
Care & Maintenance
DANGER: Contains Mercury. Do not ingest, inhale dust, or handle with bare skin excessively. Wash hands after handling. Keep in a sealed container away from heat or direct sunlight to prevent mercury vapor release.
Rarity & Value
Relatively common as an ore, but high-quality crystalline specimens or aesthetic 'bloody' matrix pieces are valued by collectors. Generally affordable but depends on the intensity of the red color.
Special Characteristics
Presents a distinct 'vermilion' color. It is the primary ore of mercury and is known for its extreme density relative to its earthy appearance.
Lore & History
Historically used as the pigment 'vermilion' in ancient art and calligraphy. In traditional lore, it was associated with alchemy and transformation, though its high toxicity makes it unsuitable for modern healing practices involving skin contact or ingestion.