38 



Case 54. Tihoolurra, Milparinlca, IBrohen Hill, Silverlon. 



Case 55. Wyalong. — This gold-field is, perhaps, better represented in the 



Southern collection, than any of the others. The series commences with the 



District, country-rock and a few special exhibits ; then succeed the gossan 



and ore from the upper levels, followed by the sulphides. 



The country-rock would be popularly known as granite. 

 Strictly speaking it is more akin to quartz-diorite, and in places 

 becomes even more basic in character. For ordinary purposes 

 hornblende-granite is a sufficiently accurate name. 4007 shows 

 it in its disintegrated weathered condition from near the surface, 

 while 6775, from a depth of 13i feet in the Welcome Stranger 

 Mine, is the solid rock.* 9136^ ferruginous quartz showing gold, 

 is of historic interest, being one of the earliest specimens found 

 by the original prospectors. 9133, a nodule of carbonate of 

 magnesia found in the sub-soil. These nodules are undoubtedly 

 of secondaiy origin, being due to the action of water. The 

 decomposition of hornblende in the country-rock would supply 

 the magnesia. 5770, 9137, a brown variety of common opal 

 showing gold. Such specimens were not uncommon in the 

 upper levels, and represent an unusual occurrence of gold. It 

 may be compared with the similar stone from Brown's Creek, 

 Blayney (page 34, case 52). 9139 from the Monte Christo is 

 manganese-stained. Passing over the diflerent varieties of 

 auriferous quartz, we come to 8118 from Kliuk's Mine, 150-ft. 

 level, quartz, distinctly chalcedonic, assaying 18 oz. of gold per 

 ton, none being visible to the eye. 9135 from Stanley's Blow- 

 should be noticed : a kernel of pyrites is enveloped by fer- 

 ruginous red quartz showing a concentric zone of free gold. 

 8224, from the Hed Flag, is cellular quartz. The cavities are due 

 to the decomposition and removal of pyrites, from which the free 

 gold contained by some of them may reasonably supposed to have 

 been derived. 8219 shows gypsum associated with free gold. 

 9132, Native copper from the Klondyke Mine (300-ft. level). 

 This mineral occasionally occurs, and is not regarded as a 



* The depth to which the decomposed rock extends depends upon various circumstances. 

 On the Wyalong field it is sometimes very considerable. 



