Mohs Hardness: 7 out of 10
Color: Occurs in many different colors. Scroll below for a list of the different varieties of quartz.
RI: 1.544 to 1.553 (very constant)
Optic Character: Uniaxial positive. Might show a bull's eye or Airy's spiral optic figure under crossed polarizing filters.
Pleochroism: Weak to moderate, colors vary depending on variety of quartz.
Spectrum: Not diagnostic
Fluorescence: Generally inert
SG: 2.66 (+0.03/-0.02)