Assertion: crystalline silica | /r/HasProperty | expensive
Facets:
value: very
type: DEGREE
value: to attain such high temperatures
type: PURPOSE
Source sentences:
text: Fused silica itself is an excellent glass, but, as the melting point of sand (crystalline silica) is above 1,700 °C (3,092 °F) and as it is very expensive to attain such high temperatures, its uses are restricted to those in which its superior properties—