A source of tips and guides for faceting Bytownite. This belongs to the plagioclase feldspar group and is considered one of the rarest amongst the members.
Bytownite (Feldspar)
Color: Pale yellow to brown
Moh's Hardness: 6-6.5
Refractive Index: 1.52-1.568
Critical Angle: 41.14°
Specific Gravity: 2.56-2.70
Cleavage: Perfect
Fracture: Uneven, can be brittle
Dispersion: .012
Heat Sensitivity: Moderate in my experience
Dichroism: Weak
Birefringence (double refraction): Weak to medium (.005-.01)
Crystal Structure: Triclinic
Treatments: Generally none
What I prefer to polishing with: Cerium oxide with a Spectra Ultralap.
Jeff's Comments: Cuts and polishes easily, use a medium fine lap like a 600 grit for roughing in because a coarse lap can sometimes aggravate cleavage. Cleavage usually is not a problem, sharp corners have a tendency to chip out sometimes during cutting.
Design Notes: About any Quartz design will work well. I prefer a deeper design and often cut Barions.
Design Links: Tzar - High dome will help improve color and sparkle
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Bytownite (Feldspar)
Color: Pale yellow to brown
Moh's Hardness: 6-6.5
Refractive Index: 1.52-1.568
Critical Angle: 41.14°
Specific Gravity: 2.56-2.70
Cleavage: Perfect
Fracture: Uneven, can be brittle
Dispersion: .012
Heat Sensitivity: Moderate in my experience
Dichroism: Weak
Birefringence (double refraction): Weak to medium (.005-.01)
Crystal Structure: Triclinic
Treatments: Generally none
What I prefer to polishing with: Cerium oxide with a Spectra Ultralap.
Jeff's Comments: Cuts and polishes easily, use a medium fine lap like a 600 grit for roughing in because a coarse lap can sometimes aggravate cleavage. Cleavage usually is not a problem, sharp corners have a tendency to chip out sometimes during cutting.
Design Notes: About any Quartz design will work well. I prefer a deeper design and often cut Barions.
Design Links: Tzar - High dome will help improve color and sparkle
