BY AV. F, PETTERD, C.M.Z.S. 55 



carats, and stones, often of remarkably good colour, are 

 not rare weighing from 4 to 12 carats. Many of the stones 

 have been cut and mounted, but the trade m them is 

 extremely limited. The sapphire has not been detected 

 in situ, although the granite of the mining districts may 

 fairly be considered its matrix. 



The amethyst and ruby of the Oriental or corundum 

 variety are not known to occur, but the Oriental topaz 

 has been obtained at Main Creek and the Weld River. 

 Prominent localities are Mt. Cameron ; Thomas' Plain ; 

 Weld River; Main Creek; Branxholm ; and Moorina; all 

 on the north-east alluvial tin-mining fields. At the Blyth 

 River, corundum occurs in the opaque form from almost 

 colourless to dirty-blue and grey. At Boat Harbour, near 

 Table Cape, clear blue, rolled fragments occur intermixed 

 with zircon and quartz. Near Bell Mount in the Middle- 

 sex district a few small fragments of opaque corundum 

 have been obtained, and the same remark applies to several 

 other localities. 



92. CossYRiTE (Titanosirtcate of Sodium, Iron, mid 



Aluminium J. 



This is a triclinic amphibole, of somewhat rare occur- 

 rence. It is found as irregular microscopic shreds, ^vith 

 prismatic and hexagonal sections, of a dark red-brown 

 colour, as an accessory in the garnetiferous-mica-solvsber- 

 gite of the peculiar alkaline rock plexus of Port Cygnet. 



93. CovELLiTE (Sulphide of Copper). 



The cupric sulphide (Cu S) is usually found as a blue 

 incrustation on other copper-bearing sulphides. It is a 

 secondary mineral, principally derived from the alteration 

 of chalcopyrite and bornite. It is commonly known as 

 indigo copper ore, since it resembles indigo in general 

 colouration. It has been found at the Cascade and at 

 Blue Tier, in association with cassiterite, in the porphyry 

 and granite rocks. At Murray's Mine, near Mt. Balfour, 

 it is a well-recognised enrichment of the prevailing yellow 

 copper ore. At the Heazlewood it has occurred in limited 

 quantity, and is known in several other localities. 



Respecting the mineral mixture of covellite, tenorite,. 

 &c., that occurs at the North Lyell Mine, Mr. R. Sticht 

 writes: " It is of special interest, because it occurs at th« 

 500-feet level of the North Lyell Mine. In that mine 



