This small sized rough from Nacozari has been enhanced using the Zachary Process, which is a less invasive treatment than stabilization. Absolutely no coloring has been added to this turquoise. This Small Size is a mixed grade, but more like #1 quality.
Turquoise is a copper-based mineral (hydrated copper aluminum phosphate). Turquoise polishes well with diamond, tin oxide or green rouge.
Sample of Small Size Mixed Quality Enhanced Turquoise from Nacozari, Sonora, Mexico