AAA Grade Quartz Carving

Crystals are graded based on color, clarity and purity. There's quartz that's almost white in color and there's quartz that is juicy in appearance. Some quartz you cannot see through and others are very see through. What does this all mean? The letters stand for the GRADES of crystal. There's B, A, AA, AAA, Gem Grade, and it goes more in depth but we are keeping it simple and basic here.  B is low grade and working up from there.  A is lower grade than AA.  AAA grade is higher than AA grade.