147 



Silicate of lime : A fibrous white mineral, very commonly found "WoUastonite. 

 ill limestone, where altered by contact with heated igneous rock. 

 In New South Wales it is sometimes associated with garnet, which 

 has resulted from the same metamorphic action. (See case 100.) 



Sidmouth Yalley, Cox Eiver, ISTewbridge, Macleay Elver. 



Amphibole. a group of silicates differing essentially from 

 the pyroxenes in crystalline form only. 



Silicate of magnesia, lime, alumina, and iron, usually of a Hornblende, 

 dark greenish colour, frequently occurring in blade-like crystals. 

 (See 1241, from Kapunda, South Australia, and 3679, from 

 Massachusetts.) 



It is a common constituent of diorite, andesite, and other 

 igneous rocks in New South Wales. Selected specimens from 

 Carcoar, Fish Eiver, Gundagai, and Glen Innes are exhibited. 

 The syenite of the Gib Eock at Bowral sometimes contains 

 patches rich in blade-like hornblende. (See case 142.) 



9391, Barrier Eange : crystals penetrating calcite. 



A green variety of amphibole, poor in alumina, occurring in Actinolite. 

 slender glassy crystals. Sofala, Mclntyre Brook, and New 

 England. 



Silicate of lime and magnesia ; grey in colour. It frequently Xremolite. 

 occurs in limestones that have been altered by the intrusion of a 

 mass of igneous rock (contact-metamorphism). Tumbarumba. 



Consisting of matted fibres ; Tasmania, South Australia. Mountain 



Cork. 

 A blue fibrous variety, becoming yellowish on oxidation, found Crocidolite. 



in South xlfrica. When silicified, as is generally the case, it 



takes an excellent polish, and forms a beautiful ornamental 



stone. (See case 15.) 



Is often a fibrous form of amphibole (see Serpentine and page Asbestos. 

 126). 



A large specimen from Eenfrew, Canada, is shown in case 120. jade. 



A very tough, massive silicate of magnesia and soda — the 

 " greenstone " of New Zealand ; a handsome ornamental stone. 

 It has been found at the Wentworth Mine, Lucknow, but this 

 variety does not take a good polish. 



