No. 21. A. "Copper ore." A fair average specimen was prepared for examination from the several lumps of ore and marked a.
a. It was submitted to analysis, and found to contain carbonates of lime
and magnesia; silica, alumina, and oxides of iron; and of—
Copper (metallic) . . . .5.72 per cent.
b. A portion of the copper mineral, from which the rock or vein-stuff had
been detached as far as practicable, was found to consist of impure
hydrated silicate of copper (bluish-green chrysocolla) and carbonate of
copper. It was assayed and found to contain of—
Copper (metallic) . . . .23.14 per cent.
No. 22. "B." A lump of soft, ochrey red-brown ironstone, coated with a thin
layer of greyish white substance. A fair average sample, inclusive of this
external layer, was prepared for examination, and was found to consist of
Peroxide of iron (per cent. ) . . .81.14
Water . . . . . . . . . . . . . . 11.50
Silica. . . . . . . . . . . . . . . 3.07
Sulphuric acid, lime, magnesia, alumina 4.29
_____
100.00
The peroxide of iron contains 56.8 per cent. of metallic iron. The greyish white substance was found to consist of silica, alumina, sulphate of lime, and a little oxide of iron and magnesia.
No. 23. "C." Lump of red ironstone associated with sand and earthy
substances, containing
Peroxide of iron (per cent.). . . 68.09
Water of iron (per cent.) . . . . . 1.93
Silica and sand . . . . . . . . . .18.17
Lime, magnesia (in small quantity), alumina,
carbonic acid, sulphuric acid (traces) .11.81
______
100.00
The peroxide of iron contains 47.66 of metallic iron.
No. 24. "D." Lump of white quartz said to contain visible gold. I did not observe any, but found a few minute specks of pyrites, and partially resembling mica.
No. 25. Lump of quartz associated with red-brown oxide of iron. It yielded no results.
No. 26. Lump of rock in which the "turquoise" occurs. There was a thin layer of greenish blue turquoise mineral on one surface, and minute seams of a similar substance throughout the specimen.
a. The layer of turquoise mineral, from which the rock or vein-stuff had been detached as far as practicable, was found to contain phosphoric acid, alumina, oxide of copper, oxide of iron, and water; which occur in turquoise.
b. After the layer a had been separated, a fair average sample of the rock was found to contain 1.69 per cent. of metallic copper. It was also assayed and found to be free from silver[7] and gold.