X, A, 1 Smith, Edding field, Fanning : Philippine Minerals 95 



Sulphur — S. 



Sulphur occurs more or less pure in characteristic yellow crys- 

 tals around solfataras and also in a very impure state mixed with 

 volcanic ash on Camiguin Island north of Luzon; on Taal Vol- 

 cano and in Sorsogon, Luzon; on Mount Apo, Mindanao; and 

 on Biliran Island. No sulphur is mined at present, but some 

 mining was carried on formerly on Biliran. 



Talc— 3Mg0.4SiO..H20. 



There are small amounts of talc associated with mica and 

 actinolite in the metamorphic region of Ilocos Norte, Luzon. 

 No local use is made of this mineral. 



Tetrahedrite — 4Cu2S.Sb2S3. 



Tetrahedrite occurs as flint-gray to tin-black crystals. It is 

 found at the old Santa Barbara mine, Mancayan, Lepanto, Luzon. 



Titanite— CaTiSiOg or CaO.TiO2.SiOj.. 



Titanite occurs as characteristic wedge-shaped crystals asso- 

 ciated with the iron-ore deposits of Bulacan. 



Topaz— (AlF)2SiO, or (A1(F, OH)2)SiO,. 



Topaz occurs in small (2-4 millimeters) pink, yellow, and 

 colorless orthorhombic crystals. It is found in placers of Para- 

 cale River, Ambos Camarines. 



TremoUte— CaMga (SiOg) ,. 



Tremolite occurs in long white to greenish fibers associated 

 with serpentine and asbestos in Ilocos Norte. It could be used 

 commercially. 



TJralite — Composition same as pyroxene save for slight change 

 in magnesium and calcium content. 



Uralite is a green alteration product of pyroxene, and is found 

 in certain igneous rocks called metadiorites, which are altered 

 gabbros. 



Vermiculite — Hydrated mica. 



Verraiculite is an earthy mica found in the metamorphic area 

 of Ilocos Norte. It has no economic value. 



Wad — An earthy mixture of manganese oxides. 



Wad is found in association with psilomelane and pyrolusite. 

 It is of no economic importance now. 



