JDMISGem Reference
Carbonate (calcite group) · Calcite

Grey-Black Calcite

Grey-Black Calcite — Calcite

Grey-black calcite is massive dark carbonate flecked with carbon or pyrite, cut as cabs, beads and carvings. Hardness 3, aggregate RI blink and instant acid effervescence identify it against black onyx, jet and black glass. A modest ornamental stone.

Colour
grey
Transparency
Opaque
RI
1.486–1.658
SG
2.65–2.75
Mohs
3.0
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