Agate is a common rock formation, consisting of chalcedony and quartz as its primary components, with a wide variety of colors. Agates are primarily formed within volcanic and metamorphic rocks.
Color banded
Crystal habit Cryptocrystalline silica
Cleavage None
Fracture Conchoidal with very sharp edges
Mohs scale hardness 6.5–7
Luster Waxy
Streak White
Diaphaneity Translucent
Specific gravity 2.58–2.64
Refractive index 1.530–1.540
