We are moving items to our new website:
CopperCanyonLapidary.com
Items marked sold may still be available there. Happy Shopping!
Petalite (Lithium
Aluminum silicate)
Color: colorless, light greenish
or pink.
Moh’s hardness: 6-6.5
Refractive index: 1.50-1.52
Critical angle: 41.5°
Specific gravity: 2.40
Cleavage: Perfect in one direction.
Fracture: Conchoidal, brittle.
Dispersion: Medium (.014)
Heat sensitivity: Low
Pleochroism: None
Birefringence (double refraction):
Medium (.012-.016)
Crystal structure: Monoclinic
Cutting: Use medium and fine
laps.
Polishing: Use tin/lead lap
with alumina or cerium oxide; or aluminum oxide Ultralaps. Run polishing
laps at slow speed.
Comments: The cleavage plane
usually doesn't cause any problems, but will only polish to a pearly luster.
Petalite cuts into bright stones with a vitreous luster.
OPAL Server
|