Turner — Unusual Minerals from the Pacific States. 345 



Si0 o soluble in Na 2 C0 3 44-8 



Fe 2 G 3 31-8 



MgO - 1-2 



H 2 .._ ._.. 22-2 



ioo-o 



The composition of the yellow-green mineral thus determined 

 corresponds nearly with chloropal. 



Diopside. — In the Palmetto Mountains in Esmeralda County, 

 Nevada, there are a few small areas of serpentine at or near 

 the contact of granite and other rocks, either acid metamorphic 

 lavas or cherts of Ordovician age. Associated with the ser- 

 pentine are bunches of limestone, and at one point a streak of 

 garnet and magnetite. 



In the serpentine was found a considerable amount of a 

 monoclinic pyroxene, which was separated and analyzed. 



Partial analysis of pyroxene No. 323 from serpentine mass. 

 George Steiger, analyst. 



Silica -_ ._ 46-04 



AUO3* 1-21 



Fe" o 3 t 5-24 



MgO 16-98 



CaO 25-23 



This pyroxene is evidently near diopside in composition, and 

 it is possible that it is of metamorphic origin from dolomite, as 

 has been shown to be the case at Montville, N. J., by G. P. 

 Merrill.;}; The serpentine is presumed to be derived from the 

 pyroxene. 



Yesuvianite. — It is well known that at the contact of granite 

 and limestone various silicate minerals often form from the 

 action of heat and vapors of the intrusive granite on the cal- 

 careous material. At such a contact in the NE. part of the 

 Silver Peak quadrangle a silicate mineral was found associated 

 with garnet and quartz. This silicate, freed from the associated 

 minerals by means of the Thoulet solution, was analyzed with 

 the following results (p. 346). Boron was looked for but not 

 detected by blowpipe test. 



Sulphates. 



Jarosite. — On the east side of Soda Springs Valley in Esme- 

 ralda County, Nevada, at the edge of the foothills by the road 

 to the Vulcan Copper mine, there is quite an amount of a 

 golden-brown micaceous mineral, the origin of which was not 



* Includes any Ti0 2 and P 2 5 that may be present. 

 + Includes any FeO, calculated as Fe 2 3 . 



% On the Serpentine of Montville, N. J., Proc. U. S. Nat. Museum, vol. xxii, 

 pp. 105-111. 



