642 



UNITED STATES MINERAL RESOURCES 



Tin deposits □„ n ■ 



^__!_.^ Beryllium deposits 



Figure 71. — Geochemical cycle of tin, western Seward Peninsula, Alaska. Number indicates maximum concentration, in 

 parts per million. For granite the concentration is the average of five samples: for individual minerals in granite it is 

 the average of three samples. In plants, the concentrations vary with plant type ; value shown is the maximum observed 

 gain over the corresponding soil. (From Sainsbury, Hamilton, and Huffman, 1968, pi. 2.) 



the world and for formulating dependable explora- 

 tion techniques. In another area near the Lost River 

 district, where cassiterite in placers is associated 

 with quartz-cassiterite veins not accompanied by sul- 

 fides, bulk stream sediments were devoid of geo- 

 chemical anomalies, even though overlying a buried 

 placer. Only panned concentrates revealed the pres- 

 ence of the lodes (Sainsbury and others, 1970). 



TIN MINERALS 



Cassiterite (SnOo) contributes almost all the tin 

 of industry, although small amounts are recovered 

 from tin-sulfide minerals, such as stannite, cylin- 

 drite, and teallite. The more common tin minerals 



are listed in table 134. This list is restricted to tin 

 minerals containing oxygen or sulfur ; tin also forms 



Table 134. — The more common tin minerals 



Geographic 

 Name Composition occurrence 



Argyrodite 

 Arandisite 



Berndtite _ 



Cassiterite 



Canfieldite 



Colusite _- 

 Cylindrite 



Franckeite 



-AgsGeSua Bolivia. 



.Complex tin silicate __ South West 



Africa. 



-Beta SnS2 Do. 



_Sn02 Worldwide. 



-AgsSnSa Bolivia, 



Tasmania. 

 -Cua(As,Sn.V,Fe,Te)S4 -Montana. 

 -PbaSn.Sb.S,, Bolivia, 



Tasmania. 

 -PbsSnsSbsSu Do. 



