106 BUILDING STONES OK QUEENSLAND. 



The sjK'C'ific gravity of this stone is 2.S4 so that its weight 

 ])er cubic foot is 177.5lbs. 



The stone is rather more coarsely crystalline than the 

 Knoggera granite and has an average grain-size of about 2nim. 

 The rock is made up of plagioclase felspar, angite and biotite 

 for the most part. These minerals can be detected easily 

 by an examination with a lens. Under the microscope the 

 fabric is seen to be granitic and the minerals constituting 

 the rock to be plagioclase, augite, biotite, orthoclase, quartz, 

 and magnetite in order of decreasing abundance (see micro- 

 jjhotograph 14, plate X). 



In comparison with the Enoggera granite it is seen 

 that the dark ferro-magnesian minerals are much more 

 abundant and the individual crystals are much larger. 

 Augite is ver}^ abundant and occurs u]) to 3mm^ in 

 leiigth ; it is generally in a fresh condition but in some places 

 it is altered to chlorite. All the minerals are \erv stable. 

 Petrologically this rock would be known as quartz-diorite. 



It has been used for bed ])lates and as a cut-water in 

 the Albert Bridge (1893-95) at Indooroopilly, for two or 

 three cour.^es in the l)ase of the Executive Building 

 (1901-05) and in the base of the Royal Insurance Building 

 (1906) in Queen Street. 



This stone has much to comuiend it ; it does not seeui 

 to have any mineralogical or structural defects, but on the 

 other hand it has a \ ery handsome appearance and looks 

 Avell when worked. Consequent!}^ a more extensi\e use of 

 this stone is to be hoped for. The outcrop is A\ithin 

 a very few miles of the Brisbane river at a ])uint from 

 which gravel barges now ply to Brisbane, so that it is 

 reasonably accessible to Brisbane. 



(ireymare (! ramie . 

 This occurs in the neighbourhood of CJreynuiie. 2<i miles 

 west of Warwick and 180 miles from Brisljane, and out- 

 crops oxer a large area. No proper quarrying has l)een 

 done, and surface })o\dders only have been worked. These 

 have been Avorketl in the immediate neighbourhood of the 

 Greymare railway station and consist of material much 

 fresher than the general mass f)f granite. The freshness 

 of the stone in these boulders right uji to their outer 



