Agate
Agate |
---|
![](//upload.wikimedia.org/wikipedia/commons/thumb/f/f2/Mossagate.pebble.750pix.jpg/240px-Mossagate.pebble.750pix.jpg) Moss agate pebble, 2.5 cm (1 inch) long |
General |
---|
Category | Quartz variety |
---|
Chemical formula | Silica, SiO2 |
---|
Identification |
---|
Color | White to grey, light blue, orange to red, black. |
---|
Crystal habit | Cryptocrystalline silica |
---|
Crystal system | Rhombohedral Microcrystalline |
---|
Cleavage | None |
---|
Fracture | Conchoidal with very sharp edges. |
---|
Mohs scale hardness | 7 |
---|
Luster | Waxy |
---|
Streak | White |
---|
Specific gravity | 2.58-2.64 |
---|
Refractive index | 1.530-1.540 |
---|
Birefringence | up to +0.004 (B-G) |
---|
Pleochroism | Absent |
---|
Agate