468 II. W. Turner — Gold Ores of Calif ornia. 



Prof. W. P. Blake* states that blende and tetrahedrite are 

 found at Carson hill, and in the Pine Tree mine in Mariposa 

 county. The latter mine directly adjoins the Josephine. 



Associated with Mariposite at the Josephine mine in Mari- 

 posa county, and at Quartz mountain in Tuolumne county, is 

 a white mineral which at some points appears to form veins in 

 the mariposite. This is probably the mineral called ankerite 

 by Silliman. An examination of this material by Dr. Hille- 

 brand shows that it is ordinary dolomite mixed with quartz 

 and not ankerite. In the Josephine mine erythrite, a hydrous 

 arsenate of cobalt, forms on surfaces and in seams of the rock 

 adjoining the vein. 



In addition to the ordinary iron sulphurets, the writer has 

 observed in the Mother lode ores in Amador county, galena, 

 blende, and arsenical sulphurets in small amounts. As a gen- 

 eral rule the ore of the large mines of the Mother lode show 

 no free gold and only iron sulphurets. Specimens showing 

 free gold and other than iron sulphides are not abundant. All 

 of the Mother lode ore would be called free milling. 



In the Paleozoic schists to the east of the Mother lode there 

 are numerous gold veins which have been worked with vary- 

 ing success. One of the most profitable of this group of 

 mines is the Sheep ranch mine of Calaveras county. The 

 country rock of this mine is a mica-schist. The mines about 

 Summersville in Tuolumne county are also in mica-schist. In 

 these mines likewise the sulphurets do not exist as a rule in 

 large amount and the ores may be classed as free milling. One 

 of the most interesting of the mines of this group is the 

 Blue Wing vein of the Willard Mining Company, north of 

 Murphy's, Calaveras county. Here in limestone is a quartz 

 vein which in places is accompanied by brown vein jasper. In 

 the Blue Wing vein are found the sulphides of mercury and 

 antimony and lead. Birdseye porphyry, in this case probably 

 an altered diorite, cuts the limestone in dikes. In the highly 

 altered slates and eruptive rocks to the west of Blue mountain 

 in Calaveras county are a group of mines, the ores of which 

 are very basic. Sulphides containing lead, silver, zinc, arsenic 

 and iron are found in the ore. At the Bonanza mine at So- 

 nora in Tuolumne county the ore occurs in pockets along a 

 diorite dike in the slates. Large masses of free gold with tel- 

 lurides occur here and iron and copper sulphides. 



At the Ilex mine in Calaveras county in Paleozoic mica- 

 chlorite- schist there is a large quartz vein having a course N. 

 80° E. Tetrahedrite and sulphides of lead, zinc and copper, 

 as well as free gold, are found sparingly in the ore. 



* California Minerals, Sacramento, 1866. 



