The Specimen Library / Under the Loupe
Onyx · Science
A name to check / banded chalcedony versus carbonate
A closer look beyond the specimen label.
← Return to OnyxC&C image archive · photograph forthcoming
No substitute photograph has been used
No substitute photograph has been used
The material, examined
What the name tells you
A name on a home-decor label may describe an appearance rather than mineral composition. This matters when cleaning a lamp, bowl or carving: a quartz care rule can be wrong for a calcite object.
A useful question at the counter
Is this chalcedony or a carbonate? If black chalcedony, what is known about color treatment?
A note for your collection
Until identity is known, avoid acidic cleaners and scratch tests. Carbonate and quartz objects need different care.
Sources & further reading
References are labeled by role. A source documenting a belief is not evidence of a medical or mineralogical effect. Reflection prompts are C&C editorial suggestions.
- Gem-A: Types of chalcedony
- C&C original crystal-practice index, 2017 archive: contemporary C&C teaching and symbolic associations.
- Handbook: Quartz properties, aggregate behavior may differ
Adjacent drawers
Related Specimens
The cabinet