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Chalcedony — specimen 0019, photo © NMNHS
Chalcedony — specimen 0019, photo © NMNHS

Chalcedonyspecimen 0019


no precise locality [Africa]

Weight: 6.14 ct; size: 12.35 | 9.33 | 6.55 mm; shape: octagon; colour: light grey; clarity: translucent; cut: fair; treatment: none.

Clean specimen; step cut style.

Other specimens
Chalcedony — specimen 0088Chalcedony — specimen 0403Chalcedony — specimen 0180Chalcedony — specimen 0510Chalcedony — specimen 0511Chalcedony — specimen 0512Chalcedony — specimen 0580Chalcedony — specimen 0591Chalcedony — specimen 0225Chalcedony — specimen 0688Chalcedony — specimen 0418Chalcedony — specimen 0558Chalcedony — specimen 0179Chalcedony — specimen 0183Chalcedony — specimen 0404Chalcedony — specimen 0265Chalcedony — specimen 0348Chalcedony — specimen 0684

More information from ‘Classification’

Traditionally defined as a fibrous cryptocrystalline variety of quartz. More recently, it has been shown that much chalcedony is a mixture of quartz and mogánite. Pure chalcedony may contain trace amounts of silanol groups.