Assertion: quartz | /r/HasAspect | a hardness of 7
Facets:
value: on the mohs scale
type: OTHER
Source sentences:
text: This is because most beach sand is mainly composed of quartz, which has a hardness of 7, while silicon carbide grit has a hardness of 9.
text: It has a hardness of seven on the Mohs Scale which makes it very durable.