Yungai is an area and a mine located in Hubei Provence, China. The story of the introduction of Chinese turquoise to the US market is told in Chapter Five of Turquoise in America Part Two 1910-1990 and in an article Turquoise in China Past and Present on the Blog of turquoiseinamerica.com.
 
This cab weighs 52.4 carat and measures 3.5cm X 3cm. It is priced at $25 a carat - $1310. It is not treated and is backed. I have assigned a TG of 89 or VHG. I purchased this stone from Ron Alexander.