454 Norman Taylor — The Cudgegong Diamond Field. 



Metallic iron. — Hackly fragments of slightly rusted metal, 

 evidently derived from the tools used. Analysis failed to detect any 

 trace of nickel. 



Wood tin. — Eare, and in small pieces. 



Titanic acid. — Probably brookite, in flat red transparent or red- 

 dish-white translucent plates, with striated surfaces, but too worn to 

 distinguish the crystalline form. The plates vary in thickness up to 

 one-twelfth of an inch, and are often one-fourth of an inch across ; 

 hardness, 6 ; specific gravity, 4*13 ; composition found by analysis 

 to be pure titanic acid, with only a minute trace of iron. 



Black magnetic iron sand. — Common. 



Black titaniferous iron sand. — Common. 



Tourmaline-schorl. — Rolled black prisms half an inch long are 

 common ; small nests of schorl in quartz pebbles rare. 



Garnet. — In minute brown icositetrahedrons, rare and only occur- 

 ring in the recent river drifts. 



Black vesicular pleonaste. — Occurs in small grains from one- 

 twentieth to one-fourth of an inch in diameter, and is very abundant. 

 It has a dull black surface, but shows a brilliant fracture. Some 

 pieces are coated bluish grey or rusty brown ; but the interior is the 

 same in all, the external differences seeming to be the result of 

 decomposition. It never occurs in crystals, nor shows any traces of 

 faces, and has no cleavage ; its fracture is conchoidal and jet black, 

 with a strong vitreous lustre ; hardness 8 ; streak grey ; composition 

 found by analysis : — 



Silica (and undecomposed) 2.75 



Alumina 64-29 



Chromic oxide 4-62 



Magnesia 21-95 



Ferrous oxide 4-49 



98-10 

 Oxygen ratio 3-2 : 1 ; Specific gravity 3-77. 

 The mineral is amorphous and vesicular. The latter character is 

 remarkable, and the grains do not all show it in the same degree. 

 One variety (the least abundant) with a lustrous surface shows it 

 best, the grains resembling a perfect cinder when seen through a 

 lens. Several pounds weight of this mineral were obtained from each 

 load of gravel washed, more especially from the newer drift. 



Topaz. — In waterworn fragments, and sometimes in imperfect 

 crystals, with terminal planes ; transparent and usually white, rarely 

 yellow or light blue. This is the largest of the associated 

 minerals, varying in size up to half an inch in diameter. 



Zircon. — In small rolled pieces, and as a fine heavy sparkling sand 

 in abundance ; transparent, brown, very pale red, or colourless. They 

 rarely exceed one-fourth of an inch, and are mostly smaller ; but are 

 found higher up the river, and above the diamond fields, in pieces 

 of much larger size and richer in colour. 

 Corundum. — 

 Var. (a). Sapphire. — Transparent, blue, green, yellowish, and particoloured; 



too small and of bad colour to be of value. 

 (b). Adamantine spar. — Hair-brown and black with chatoyant lustre. 



