104 
“ Tlie ridge is much steeper on the eastern than on the western fall. The bed. 
of limestone is 70 feet south of this cutting. It is an open quarry, with a face 30 feet 
in width and 22 feet in height. 
“In the face of this quarry there is a large mass of crystallized cal cite, 11 feet 
in height from the floor and 27 feet in width. Magnetite occurs on either side of this 
calcite, which appears to have filled a large cavity. 
“ There are numerous pipe-shaped and circular cavities ; these, and all the joints, 
are filled with a fine dust, consisting chiefly of black oxide of manganese and a little 
cobalt, from which fact this working place has received the name of the ‘cobalt cutting. 
The percentage of cobalt is very small. Dr. March, of Maryborough, gives two analyses 
of this black dust : — 
Bismuth ... 
Cobalt 
Nickel 
Iron 
Manganese 
Lime and magnesia 
Silica 
44'45 
4'76 
0-68 
13-65 
9-75 
19-92 
6-90 
100-00 
“ Of a second sample he says — ‘ It consists of black oxide of manganese with 
5-97 per cent, of cobaltic oxide.’ Messrs. Johnson and Matthcy return only 2 per cent, 
of cobalt. The first sample was exceptionally rich in bismuth. 
“ Native bismuth, the oxide and carbonate of bismuth, and at times a 
little sulphide of bismuth, occur in this dust. The native bismuth is generally 
adhering to the calcite, and is often in the form of ‘casts’ of the rhombohedral 
crystals of calcite, showing that it must have been deposited there subsequently to 
the calcite. 
“ Four pieces of native bismuth were found in a small cavity, weighing together 
36 lb. ; small pieces up to 4 or 5 oz. in weight are continually being obtained. 
“ Small crystals of aragonite often encrust the calcite of these pipes. Some of 
these pipes are 2 or 3 feet in diameter and several feet in length. 
“ During my visit oxide of manganese was found coated with the mineral 
erythrine — a hydrated arsenide of cobalt. This mineral is of a peach-blossom colour, 
and reniform in shape. At present it has only been found in small quantities ; when 
found in quantity it is very valuable for the manufacture of ‘ smalt’ — a blue pigment. 
I believe this is the only occurrence of this tnineral known of in Qxioensland. 
“ Around the calcite is a layer of soft material rich in bismuth ore, and above 
this layer is a quartzose rock containing arsenical pyrites and specks of metallic 
bismuth. This rock will require crushing machinery to extract the bismuth if found in 
sufficient quantities. Near the mouth of the cutting is some jasperized quartzose rock. 
“ No. 3 Cutting — known as the gold cutting — is on the western slope of the 
ridge. It is 105 feet south-west of the face of No. 1 Cutting. It is almost entirely in 
a soft aluminous rock— probably a decomposed porphyry. Near the face there is a 
band of decomposed granite, which carries a little gold and dips to the south. A mass 
of magnetite lies above the aluminous rock. Carbonate of bismuth occurs in this 
cutting ; it is coloured green with silicate of iron. 
“ Gold has been traced along the surface, by means of small pot-holes, between 
this and No. 1 Cutting. The prospects, however, are very small, and do not repre- 
sent more than 2 dwt. to the ton. The manager reports that he has quite late ^ 
