On the Ornamental Stones of the Colony. 83 



be considered as a new rock as well as a new mineral species. 

 Its colour is given by the sesquioxide of chromium, which 

 is probably derived from the chrome iron ore, a mineral 

 abundant in the neighbourhood of Heathcote. 



Gabo Island Granite. 



This rock probably occurs as a dyke. Its mineral pro- 

 perties place it into the class of syentic granites. On the 

 mainland it becomes more and more like a true granite in 

 its composition. 



The stone is so well known in Melbourne that it needs 

 but a passing notice. It being used at the base of the 

 Post Office, where it may be seen in a trimmed and 

 untrimmed state, and at the Australasian Insurance offices, 

 where there are some beautifully-polished pillars of it. It 

 is very hard and tough, so much so as to prevent it coming 

 into general use for building purposes ; but its toughness 

 renders it extremely useful for ornamental building pur- 

 poses exposed to the weather or wear. A similar stone 

 occurs at the head of Nuggetty Gully, Dais}^ Hill. 



Geelong Greenstone. 



Attention was first called to this stone many years ago 

 by Mr. Daintree. In a report of his published in 1863, he 

 says, li To the greenstone of the Geol. \ s. 24 S.E., I wish 

 to call the attention of sculptors and workers in ornamental 

 stones. Since, though hard to work it takes a beautiful 

 polish, and the play of colours is little inferior to verd- 

 antique." Though this notice was published five years ago 

 only a few cabinet specimens have been cut and polished. 

 Some of these taken to England and the Continent were 

 much admired. Its toughness and closeness of texture 

 would permit of its being used for many articles of jewellery. 

 The fine play of colours is due to the Labradonte felspar, 

 which constitutes a large per centage of the general green 

 colour of the rock and is due to anonll with some chlorite. 



D 



Lancefield Greenstone. 



This large dyke-like mass of diorite (J-sheets 5 S.E., and 

 5 N.E. ; the latter unpublished), forming a high spur, with a 

 meridional direction, from the Great Dividing Hange, is very 

 variable in its lithological character. Mount William, at 

 the extreme northern and highest part of the range, and at 

 its junction with the Great Dividing or Coast Range, is com- 



