Assertion: amethyst | /r/HasAspect | a hardness of 7
Facets:
value: on the mohs scale
type: OTHER
Source sentences:
text: An amethyst has a hardness of 7 on the Mohs scale, so it is harder than your fingernail or a penknife, if either of these can scratch the gem in question, it is not a real amethyst.