Assertion: chalcedony | /r/HasProperty | tough gemstone
Facets:
Source sentences:
text: Chalcedony is a tough gemstone, good for all jewelry applications.
text: Since chalcedony is one of the tougher gemstones, cutting does not present any of the usual problems tor the lapidary.
text: Chalcedony is a tough gemstone, good for all jewelry applications.