Question: how to tell the difference between a quartz crystal and a diamond?
Answer: Diamonds are isometric whereas quartz is hexagonal. Both of them have the transparency scale of transparent to opaque. The gravity of diamond is 3.1-3.5 whereas quartz have 2.6 '“ 2.7. Diamond is adamantine with greasy luster whereas quartz can have vitreous, resinous, adamantine and dull luster.