Case 90. 



Molybdenite. 



Case 90. 



Sntile. 



Sphene. 



Perovskite. 



124 

 MOLYBDENUM.* 



Sulphide of molybdenum: E,ussia>5 Canada, Saxony. 



TITANIUM. 



Oxide of titanium. 



7320, 1251, crystals from Soutli Australia. The small crystals 

 show the characteristic form moderately well. 



6108 ; Vermont, U.S.A. ; in strings traversing rock-crystal. 



6124, 3054 ; massive 7'iitile from Norway and Russia respec- 

 tively. 



Silicate of titanium and lime ; a wedge-shaped mineral, fre- 

 quently found in granite and syenite, and sometimes mistaken 

 for rutile. It has some commercial value. The specimens are 

 from Canada and the Northern Territory of South Australia. 



Titanate of lime and iron ; a rare mineral, crystallising in 

 well-formed cubes. — 6910, Russia. 



Case 92. ALUMINIUM. 



This beautiful metal, characterised by its extreme lightness,, 

 is well known ; nevertheless, the variety of uses to which it can 

 now be put, as esemplified by the exhibit of manufactured 

 articles exhibited here, will no doubt be a surprise to many. 



Aluminium is, next to oxygen and silicon, the most 

 abundant element in the earth's crust. It enters into the 

 composition of innumerable minerals, usually in combination 

 with silica ; every common clay, for instance, contains a high 

 percentage of it. The metal can be extracted from any of its 

 compounds, but in its silicate condition this extraction is much 

 too difficult and costly for commercial purposes. In practice 

 only two ores are used, viz., lauxite and cryolite. The process 

 of extraction is an electrolytic one ; consequently aluminium 

 works 

 generating poAver can be had. 



re situated in districts where a good fall of water for 



* For uses and description, see page 87. 



