Blue Gem is the name of several turquoise claims. The most famous is the Blue Gem mine near Battle Mountain NV. The story is told in Turquoise in America Part Two, 1910-1990.
 
This pair of cabochons weigh 5.6 carats and measures, each, 1.5cm X 0.75cm and 1.25cm X 1cm. They are not treated. One is not backed and the other is partially backed. They are priced at $25 a carat or $140. I have assigned a TG of 82 or HG, High Grade. These stones came from the collection of Rex Arrowsmith to Forest Fenn to Marc Howard to me.