190 THE MINERALS OF NEW SOUTH WALES. 



Class II. 

 Sulphur. 



Native Sulphur. 

 Occurs in small quantities as a sublimate from the vents of Mount 

 Wingen, the so called " Burning Mountain," in association with 

 iron sulphate and various other salts. 



Class III. 



Salts. 



Common Salt. 



Chem. comp. : Sodium chloride. Common in most spring 

 waters ; occasionally found as an incrustation from the evaporation 

 of lakes and waterholes. 



Natron. 



Chem. comp. : Hydrated sodium carbonate. Said to occur as a 

 deposit from the Mud Wells in the Namoi Scrub. 



Class IV. 



Earthy Minerals 



Barytes. — Heavy spar. 



Chem. comp. : Barium sulphate. Rhombic system. It occurs 

 with fibrous and massive green carbonate of copper, copper 

 pyrites, and galena, at Cambalong, Merinoo. 



Selenite, or Gypsum. 



Chem. comp. : Hydrated calcium sulphate. Rhombic system. 

 Found crystallized in clay on the Darling River. Also on the 

 Bogan River. Of commercial value for the manufacture of Plaster- 

 of-Paris and other cements. 



Arragonite. 



Chem. comp. : Calcium carbonate. 



Rhombic system. Good crystals of this form of carbonate of 

 lime are perhaps more common than of the former mineral calcite, 

 especially in connection with stalactites and as enclosures within 

 the amygdaloidal cavities of basalt. 



Beautiful groups of crystals and bunches of flos ferri have been 

 obtained from the limestone caves at Lob's Hole, the Coodradigbee, 

 the junction of Cotton's River and the Murrumbidgee ; and from 

 near Bungonia. It also occurs at the Cataract River, and fair 

 specimens of stalactitic arragmite are to be seen at Port Hacking. 

 The more or less spherical concretions termed " cave pearls" by 

 Professor Boyd Dawkins, F.R.S., are also found in some of the 

 above caves notably from those at the Coodradigbee. 



