JDMISGem Reference
Man-made product · Glass (gem imitation)

Glass — Grey-Black

Glass — Grey-Black — Glass (gem imitation)

Man-made glass imitating black onyx, obsidian, jet and melanite garnet - identified by bubbles, swirls, mold seams, low hardness and single refraction.

Colour
grey
Transparency
Transparent
RI
1.470–1.700
SG
2.30–4.50
Mohs
5.0–6.0
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