3. “On the General Association of Grains of Gold with Native Copper,” by William Skey.
The author had tested the copper ores or rocks of D'Urville Island, Aniseed Valley, the Dun Mountain, and the Maharahara Ranges, Napier, and uniformly found a few specks of gold in each of these specimens, wherever native copper was present; and he also found that these gold specks were always the more numerous in the vicinity of the copper. The Aniseed rock was eminently chloritic, and did not contain any quartz, or indeed any free silica at all; neither hematite nor iron pyrites, the usual concomitants of gold; and it is not a rock that one would expect to find this metal in. In the heart of a solid nugget of almost pure copper were found several specks of gold, which must have been in absolute juxtaposition with the copper; yet he was unable to find that any gold had alloyed with the copper. The copper was remarkably pure, and gave no indications of being alloyed with either gold or silver.
Upon these results the author bases the hypothesis that gold in separate aggregations is a usual or constant associate of native copper; and in the particular instance of the native copper he examined (from the “Champion” lode), that it was deposited by an elect-retyping process, and subsequent to the date at which the gold was formed in the rock.
The gold obtained from the Aniseed and the “Champion” lode specimens was exhibited at the meeting, and attention was directed to the fact that one of the specks obtained from the Aniseed crushing had the colour of an English sovereign, showing that it was likely to contain copper to the extent of some 10 per cent., a very high proportion for native gold.