Genth.] 4b [ 0ct< 2 , 



The analysis gave : 



Si0 2 = 25.01 



ZnO = 67.42 



H,0 = 8.32 



100.75 



17. Titanite. 



Some time ago Mr. J. A. D. Stephenson, of Statesville, N. C, sent me a 

 fragment of a crystal of titanite from the mica schist of the neighborhood, 

 which also carries a beautiful variety of sunstone-oligoclase. 



It was IS™™ broad, 2 mm thick, of a yellowish-white color, a greasy, 

 vitreous lustre and a sp. gr. of 3. 477. 

 The analysis gave : 



Si0 2 = 29.45 



Ti0 2 = 38.33 



Fe,0, = 1.61 



MnO| 



MgO| - 



CaO = 29.11 



traces 



29.11 

 Ignition 0.60 



99.10 



18. Vanadinite. 



The vanadinite from Wanlockhead, Scotland, occurs associated with cal- 

 amine, a pale, greenish fibrous coating of pyromorphite, and rarely with 

 minute black crystals of descloizite, in brownish-yellow barrel-shaped 

 hexagonal prisms, generally united into globular groups, the surface of the 

 globules often perfectly smooth and not showing a trace of the form of the 

 crystals which produce them. They have been analyzed by A. Frenzel 

 (Jahrb. Min., 1875, 673), but as it is very difficult to get material perfectly 

 free from admixtures, some of his analyses do not fairly represent the com- 

 position of vanadinite. As I had some perfectly pure globules, I made an 

 analysis which gave : 



CI = 2.53 



PbO = 78.39 



As 2 5 = 0.34 



P 2 5 = 0.27 



V,O s = 18.04 



99.57 



10. Annabergite. 



In a previous paper, read before this Society, August 18, 1882, 1 mention 

 under niccolite that an apple-green mineral is found with it at the Gem 

 Mine, near Silver Cliff, Colorado. 



