108 BITILDING STONES OF QUEENSLAND. 



undergone a niovemeTit ])iior to its final consolidation as 

 the minerals have been orientated in a definite manner. 

 This is particularly noticeable Avith the biotite, the flat 

 flakes of Avhich are arranged in a parallel manner. 



The result is that the stone has a \ery different apjiear- 

 ance according to whether it has been worked with the rift 

 or the grain. When Avorked with the rift, that is parallel to 

 the flat flakes, the large flat flakes of black mica are very 

 pronounced and the rock has a distinctly spotted appear- 

 ance ; when worked in any other direction the thin edge 

 only of the dark flakes shoAv up and render the stone a lighter 

 grey than is perhaps desirable. The stone takes an 

 excellent polish which may be seen in the steps of the 

 GoA'ernment Savings Bank. 



This is probal)ly the best grey granite Avhich has yet been 

 AA'orked in Queensland, and although it lacks " relief "' 

 owing to the paucity of the dark minerals it has a clean 

 black and Avhite appearance, is quite coarse enough in the 

 grain and is exceptionally free from either basic or acid 

 segregations. Its Avorkiiig qualities seem to be excellent 

 so that the stone may quite Avell be used a great deal in 

 the future. The distance from Brisbane and the absence 

 of a proper quarry are factors against its development. 



The resistance to crushing has not yet been determined, 

 but its densit}^ has been measured and is 2.()0 giving a Aveight 

 of 1661bs. to the cubic foot. 



A chemical anal3'sis Avas carried out by Miss lima 

 Sterne, B.Sc, and the results are shown in the table on 

 page 150. 



The calculated mineral composition or norm is, 



Quartz 3y.3<) 



Ortlioclase H.:U 



Albitc- 2(j.i<) 



Anorthitf 1I.4(» 



( 'orundiun . . . . . . G.99 



Hypersthene . . . . 3.43 



Magnetite . . . . . . 2.78 



Ilmenite . . . . . . 0.40 



Water U.72 



Total . . . . 99.0S 



C'las.sifieation : I. 3. 3(2). 4. near AlshacJiose. 



