Sterrett — Tourmaline from San Diego County, Cal. 459 



Art. XLIII. — Tourmaline from San Diego County, Cali- 

 fornia ; by Douglas B. Sterrett. (With Plate XXIY.) 



The tourmaline crystals to be described in tins article are 

 from Damaron's Ranch, four miles northwest of Mesa Grande, 

 San Diego County, California. A representative collection of 

 over one hundred and sixty specimens given to Prof. Penfield 

 by Mr. Ernest Schernikow of New York, and deposited in the 

 Brush collection of the Sheffield Scientific School, was used 

 for most of the investigation ; which is here directed chiefly 

 toward the study of crystal form. Additional notes were ob- 

 tained from a brief examination of the collection on exhibition 



at the Natural History Museum, New York, loaned by Mr. 

 Schernikow, and from the choicest crystals in Mr. Schernikow T> s 

 possession. The crystals have evidently come from a pegmatite 

 vein, as they are often associated with large quartz and feldspar 

 crystals and bunches of lepidolite mica. They far surpass the 

 crystals of Paris and adjoining localities in Maine in perfec- 

 tion of crystallization, and those of Had dam Neck, both in 

 size and crystallization. It is also probable that no other 

 locality produces stones with more varied and beautiful colors. 



Am. Jour. Scl— Fourth Series, Tol. XYII, No. 102.— June, 1904. 

 31 



