Mica Discs
마이카 디스크
Mica grades from V-1 to V-5 with V-1 being the highest quality.
V-1
Clear, hard, of uniform color, nearly flat, free from stains, foreign inclusions, cracks and other similar defects.
V-2
Clear and slightly stained. May contain slight crystallographic discoloration and very slight air inclusions in one fourth of the useable area.
V-3
Fair stained. Hard, of uniform color, may contain slight waves, slight crystallographic discoloration, and medium air inclusions in not more than one half of the useable area.
V-4
Good stained. Hard, of uniform color, may contain medium waves. Slight crystallographic discoloration and medium air inclusions in not more than two thirds of the useable area.
V-5
Stained A quality. Hard, may contain medium air inclusions, uniformly distributed in the useable area, slight green vegetable stains and medium waviness.