114 BUILDING STONES OF QUEENSLAND. 



The situation of the mass alongside the railway line 

 and above it in level is very advantageous, whereas the 

 distance from Brisbane of 70 miles only is reasonable. 

 The remarks made earlier as to the use of the Glass 

 House Mountains stones might be made with advantage 

 here also. 



This stone is worthy of investigation and the use of 

 our rhj'olites and trachj'tes for the proposed Town Hall 

 is worthy of much consideration. 



The rock is practicallj'^ non-jDorous and would have a 

 reasonably high resistance to crushing. The specific 

 gra\ity is 2.43 giving a stone weighing only 1521bs. per 

 cubic foot- — a light stone. 



Imjwrted " Trachyte.'' 



The only imported " trachyte " used in Brisbane is 

 the Bowral "■ trachyte " from New South Wales. Strictly 

 speaking this is not a trachyte but a syenite. It is a dark 

 olive-green or dark grey in colour and of finer texture and 

 more homogeneous nature than our granites. It takes a 

 very fine polish. 



It has been used in Brisbane, in conjunction with the 

 Sj'dney sandstone, in the E.S. & A. Bank, in Eagle Street 

 (1913), where it has been used in the base and the front to 

 the first cornice. The base courses of Parbury House, 

 in Eagle Street (1915), are of this stone, also the front of 

 the Colonial Mutual Insurance Building, in Queen Street, up 

 to the first cornice. In the latter building and in the 

 E.S. & A. Bank the very fine polish the stone takes is 

 well seen. 



BASALTS. 



Toowoomba Basalt. 



This has been used in Toowoomba for rubble work but 

 apart from that, to a very little extent for structural 

 purposes. It is used extensively, however, for guttering 

 and kerbing. The quarrj^ is on the Range and shows 

 magnificent columnar structure. This structure is availed 

 of in quarrying the stone and in working it up. 



The basalt is an olivine basalt and occasionally con- 

 tains pockets of olivines which are eagerly sought for gem 

 purposes (see microphotograph 7, plate IX). 



