Ruby ↗
Mineral variety
Ruby is the red variety of corundum. A small rough crystal and a bright faceted gem share that identity, even when their clarity and apparent color are very different.
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Crystal Guide / All families
One mineral species and its gem varieties
Corundum · ruby & sapphire.
Ruby and sapphire are varieties of Al₂O₃ corundum. Keep their individual color, treatment and buying guides.
Keep each chapter’s scientific identity: a family, species, variety, trade label, rock and fossil are different kinds of names.
Sapphire ↗
Mineral variety
Blue is sapphire’s most familiar color, but sapphires can also be pink, yellow, green and other colors. The name belongs to the corundum family rather than one shade of blue.
Chip Clark, Smithsonian staff · Public domain · Display cropCorundum ↗
Mineral species
Corundum is aluminum oxide, Al₂O₃. Ruby is its red gem variety; sapphire covers other gem colors. An opaque or small labeled specimen is not automatically natural gem-quality ruby.
Ra'ike (see also Ra'ike on de.wikipedia · CC BY-SA 3.0 · Display cropRuby in zoisite ↗
Rock / mineral association
Ruby corundum occurs with green zoisite and sometimes dark associated minerals. This is an association of different minerals, not a new ruby variety or a single uniform formula.
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