84 The Philippine Journal of Science i»i6 



Azurite— Cu, (OH) ^ (CO,) ,. 



Azurite occurs as minute blue crystals in some copper deposits 

 of Pangasinan, Batangas, and Mindanao, 



Baltimorite — H^Mg.SioOj. 



Baltimorite is a white to bluish fibrous mineral associated with 

 serpentine. It is found in Ilocos Norte. It could be used for 

 steam packing and roofing material. There is no production 

 in the Philippines. 



Barite— BaSO,. 



Barite is reported from Mancayan as a vein mineral by A. 

 J. Eveland. 



Basonite — SiO,. 



This mineral is a velvet-black variety of flint known as "touch 

 stone" or lydian stone. It could be used for testing the purity of 

 gold. One sample, No. 176, is in the collection of the Ateneo de 

 Manila. 



Beryl (emerald)— Be3AL(Si03),;. 



Small and imperfect specimens are reported from Mindanao, 

 but nothing definite is knowTi regarding the locality. 



Biotite— (H, K).(Mg, Fe)2ALSi30i,. 



Biotite occurs in various igneous rocks in the Philippines in 

 small crystals, principally in Paracale granite. No economic 

 deposits are known here. 



Bituminous coal — Complex composition, principally oxygenated 

 hydrocarbons. 

 Bituminous coal is found in seams from a few centimeters to 

 several meters thick in Cebu and Mindanao. Formerly there was 

 a moderate production in Cebu. There is none in Mindanao. 

 One specimen from Dumanquilas Bay, Mindanao, shows columnar 

 structure. 



Bomite — CUjEeS^. 



Bornite occurs massive to finely crystalline in quartz veins. 

 It is probably secondary in origin. This mineral is found in 

 several of the copper deposits in the Islands. An excellent sam- 

 ple comes from Quien Sabe claim, Suyoc, Mountain Province. 

 There is development work in the Philippines but no production. 



Calcite— CaCOj. 



Calcite is generally massive without crystalline faces, but 

 some splendidly crystallized samples of "dog tooth" spar have 



