Assertion: chalcedony's luster | /r/HasProperty | subvitreous
Facets:
Source sentences:
text: A conchoidal fracture surface on crystalline quartz will be extremely smooth and reflect enough light to produce a vitreous luster; however, a conchoidal fracture surface on microcrystalline quartz will not be as smooth and will scatter more light, thus its luster will be dull or subvitreous.