Lone Mountain is an iconic turquoise mine considered one of the Seven Classic Mines of Nevada. The history is found in Turquoise in America Part Two 1910-1990.
 
This cabochon weighs 3.1 carats and measures 1.5cmX 1cm. It is priced at $80 a carat or $248. It is not treated and backed. I have assigned a TG of 91 or GG. I purchased this from Greg Fink who purchased from the miner.