Topaz's crystal habit takes many forms. It can display a range of slender and long crystals to bulky and short. There can also be variation in the terminations displaying blunt, pyramidal, chisel, or wedge-shaped terminations. The perfect cleavage {001} in topaz breaks no Si-O bonds within its structure and only breaks Al-O and Al-F bonds. This cleavage is diagnostic for this mineral. The 2V optical angle in topaz can range from 48° to 69.5°. Low fluorine content yields a smaller angle and high fluorine content yields a larger angle.
Topaz's crystal habit takes many forms. It can display a range of slender and long crystals to bulky and short. There can also be variation in the terminations displaying blunt, pyramidal, chisel, or wedge-shaped terminations. The perfect cleavage {001}. in topaz breaks no Si-O bonds within its structure and only breaks Al-O and Al-F bonds. This cleavage is diagnostic for this mineral. The 2V optical angle in topaz can range from 48° to 695°. Low fluorine content yields a smaller angle and high fluorine content yields a larger angle.