146 



Prehnite. 



Phacolite. 



Stilbite. 



Natrolite. 



districts, but they have not "been examined yet. They can be 

 obtained occasionally in some of the quarries round Sydney. 



Hydrated silicate of alumina and lime, differing from other 

 zeolites in containing less water, and in its greater hardness 

 (H = G). Pine specimens have been obtained at Prospect 

 (Sydney "Waterworks) and at Dapto, and are exhibited in case 

 144. On account of its hardness, prehnite takes a good polish ; 

 a polished piece is exhibited here. 



In the basalt quarries of Melbourne a great variety of beautiful 

 zeolites is obtained, a number of which are exhibited ; in parti- 

 cular might be noted the pretty ]ittle j^^ificol He. 



Hydrous silicate of alumina, lime and soda, 5012, fine 

 specimens from the Liverpool Plains. 



Hydrous silicate of alumina and soda. Lochinvar ; a magniii- 

 cent specimen. 



In case 119 fine specimens of various zeolites from Nova 

 Scotia. 



GROUP III. 



Minerals consisting largely of silicates of iron, 

 magnesia, and lime. 



Case 97. Pthoxene. — A group of silicates varying in composition. A 

 number of good crystals from Canada here and in case 119.* 



Au^te. Silicate of lime, iron, and magnesia essentially ; 813, Albury. 



Augite is sometimes found in lumps in basalt. 



Enstatite. Silicate of magnesia ; Bamle (Norway). 



Bronzite. A fibrous enstatite, with a bronzy lustre ; Consols Mine, 



Broken Hill. 



Jeffersonite. Manganese-pyroxene ; Pranklyn (New Jersey) . 



Diallage. A fibrous pyroxene with a sub-metallic lustre ; Gundagai. 



Spodiunene. Silicate of alumina and lithia ; South Dakota. This mineral 



sometimes occurs in crystals of enormous size. 



* A crystal of pyroxene, with crystallog-raphic description, will be found in case 33. 



