Assertion: fire agate | /r/HasAspect | a hardness of 6.5 to 7
Facets:
value: like other chalcedony quartz gemstones
type: OTHER
value: on the mohs scale
type: OTHER
Source sentences:
text: Like other chalcedony quartz gemstones , fire agate has a hardness of 6.5 to 7 on the Mohs scale; a specific gravity of 2.59 to 2.67; and a refractive index of 1.530 to 1.540.