Template:Sardonyx

From The Gemology Project
Jump to: navigation, search
Sardonyx
Chemical composition SiO2 Silicon dioxide
Crystal system Trigonal
Habit (edit me)
Cleavage Poor
Fracture Very brittle, conchoidal
Hardness 7
Optic nature (edit me)
Refractive index 1.544 - 1.553
Birefringence 0.009
Dispersion 0.013
Specific gravity 2.65
Lustre Vitreous
Pleochroism None