Assertion: chalcedony | /r/MadeOf | trace elements
Facets:
Source sentences:
text: when pure, many chalcedony contain trace elements or microscopic inclusions of other minerals, lending it a variety of colours, many of which have other names: agate, bloodstone, carnelian, chrysoprase, fire agate, heliotrope, jasper, onyx, sard, and sardonyx.