90 



Fine typical specimens of the ordinary variety and fhat 

 known as " peacock ore" (from the iridescent tarnish exhi- 

 bited by some of the fractured surfaces) are obtainable at 

 the Moonta Mine. The analyses of both varieties prove the 

 identity of composition, viz., that represented by the formula 

 Cu^S, FeS,, FeS. 



The results of the analysis of specimens of this ore from the 

 Moonta Mine are given below. (No. i. is the aualysis of the 

 untarnished variety, and No. ii. that of the peacock ore. No. 

 III. shows the theoretical composition of pyrite deduced from 

 the formula given above. 



I. 



Copper 34-21 



Iron 30-65 



Sulphur 35-16 



Insoluble silicious residue 0-50 



100-52 100-15 100.00 



Copper pyrites is reported by Tate as occurring in quartz 

 veins in the metamorphic rock in the neighbourhood of the 

 Peake, Central Australia, while it is noted by Burr as occurr- 

 ing (generally variegated) as follows : — At the Montacute 

 Mine and all the lodes in its vicinity, Eapid Bay, Flaxman 

 Valley, Hutt Eiver &c. 



AzuEiTE (Bhoe Carhonate of Copper). 

 This mineral occurs pretty generally in the copper lodes of 

 the colony, with the exception of those on Yorke Peninsula, 

 where it is rarely met with. The Burra Burra Mine and 

 Kapunda Mine were at one time noted for the quantity of this 

 mineral which they produced. It has also been found at the 

 Blinman Mine, Tudanamutana Mine, &c. &c., and near 

 Franklin Harbour and other places on the west coast of 

 Spencer G-ulf . 



Malachite 

 Occurs crystallised in ascicular crystals at the Ehondda Mine, 

 and in brown iron ore at the Wallaroo Mine ; also in the same 

 form in the so-called "red jasper rock" at the Yudanamutaua 

 Mine. This red jasper is opal, enclosing red oxide of iron, 

 and from an examination of thin sections under the microscope 

 I am inclined to think that we have had here a spongy mass of 

 oxide of iron (probably the cap of a lode) into which silica in 

 the form of opal has infiltered and thus enclosed the oxide of 

 iron). Ulrich mentions the occurrence of this mineral in 

 acicular crystals at the Oratunga Mine. 



Nodular and lenticular-shaped masses, with a radiated 



