Rough Turquoise

The basin and range province of Southern New Mexico and Arizona has a long history of mining.  The north/south mountain ranges which rise in sharp relief to the broad flat valleys between them have been sources of minerals for thousands of years and copper deposits with associated turquoise mines are found in both Arizona and New Mexico. While out walking a friends property this caught my eye (see image below), it is a  piece of rough turquoise.  There is a matrix of dark stone (limestone?) and a white crystalline material associated with the turquoise.  Turquoise is known from around Bisbee and the Dragoon Mountains northeast of Tombstone in the Sulphur Springs valley in Arizona to the west and also from Hachita to the east.  References to turquoise in the San Simon Valley are 2 sites.  One is up by Safford in a pipe-shaped porphyry copper deposit in a completely volcanic environment.  While the other is the Johnny Bull Mine in the Peloncillo Mountains, north of Granite Gap.  The presence of limestone and the green color would suggest this piece is from either east or west of the San Simon Valley.  There is a variety of deep greens and some blue which would suggest Bisbee as the original source location for this piece of turquoise, in addition much of the turquoise from Hachita is a paler green color, but early material was reportedly blue.  Whatever the source it is a nice find and since fragmentary turquoise jewelery has been found in the vicinity, this specimen may have been transported here in pre-colonial times and was lost at some point only to be found by a careful eye hundreds of years later. 

One inch nugget of rough turquoise from the San Simon Valley