Assertion: cryolite's hardness | /r/HasProperty | a specific gravity density
Facets:
Source sentences:
text: Gemologically, clinohumite has a hardness of 6 on the Mohs scale; a specific gravity (density) ranging from 3.2 to 3.4, similar to that of diopside; and a refractive index ranging from 1.631 to 1.668, between that of apatite and peridot.