BY THE REV. J. MILNE CURRAN. 183 



2. Apatite. — Apatite occurs as microscopic needle-shaped bodies 

 in the quartz and felspar crystals of granite. It is very conspicuous 

 in some slices. 



3. Quartz. — Quartz is very abundant in the district, and is 

 found as veins in the slate rocks adjoining the granite, from a few- 

 inches up to some feet in thickness. It may be easily studied in 

 the slate hills about Peel, eleven miles north of Bathurst, and 

 over the country five miles south of Perth. There are large 

 quantities of water-worn quartz on the various terraces that the 

 river has left in eroding its way from the level of the Bald Hills 

 to it present bed. It is almost unnecessary to refer to it as a 

 constituent of the granite. In fine, a very pure form of silica is 

 found, as silicified wood, in drifts that have been denuded of a 

 covering of basalt. 



4. Garnet. — Garnet, the exact species not determined, occurs in 

 the liver sand, and when sand or gravel is washed for gold 

 some garnets are always found. It occurs also as inclusions in the 

 felspars of the granite. 



5. Olivine. — This mineral is only known as a constituent of the 

 basalt ; it rarely attains macroscopic dimensions, but under the 

 microscope it is found in crystals, relatively so large as to give the 

 basalt a micro-porphyritic structure ; this is well shown in the 

 rock-slices, Plate xiv. In polished slabs of basalt it can be detected 

 as specks, somewhat darker than the matrix, and easily acted on 

 by warm hydrochloric acid. Infusible before the blowpipe ; com- 

 pletely soluble in hydrochloric acid ; olive-green in colour ; colour- 

 less by transmitted light. 



6. Topaz. — Commonly found with the gem sand washed from the 

 alluvial deposits in searching for gold. I have only met with small 

 stones. 



7. Prehnite. — A pale green to almost colourless and translucent 

 mineral was found, associated with calcite, filling a fissure in 

 partly decomposed granite at the water-works. I am indebted for 

 my specimen to Mr. W. J. Clunies Ross, B.Sc. It answered as 

 follows to the tests applied — Streak : colourless, Hardness : 6, 





