Persian turquoise has a long history. It was the first turquoise to be mined as early as 7000 BCE. While the mines are located in Iran the turquoise is known as Persian.
 
This cabochon weighs 38 carats and measures 2.5cm X 2.3cm. It comes from the Kerman area and shows the pyrite associated with that area. It is not treated, not backed and cut in the Persian manner. The cab is priced at $50 a carat or $1900. I have assigned a TG of 82 or HG. I purchased this stone from Shahriyar Zamansani.