The Pamphlet Collection of Sir Robert Stout: Volume 40
Cinnabar, or Quicksilver ore, is found in all the creeks or gullies leading from a depression in the Waitahuna heights. The ore is found in the gravel, and in a strange looking quartzose formation at the base of the mountain. Party after party has explored the locality in search of the lode, shafts have been sunk, and tunnels driven in several directions, but the first indication of anything like lode stuff was found by the writer not many months ago in the shape of an outcrop of wad or the black oxide of manganese. As the outcrop of wad determines the existence of a fissure, it is quite possible it may lead to the more valuable ore. It is intended to follow the outcrop along its course and sink on its dip, but such work means money, and ways and means have to be considered. In view of the importance of the ore, and its favourable situation, (only three miles from the Waitahuna copper mine, and 12 miles from the railway station), the discovery should not be neglected. Should the outcrop of wad lead to the permanent home of the cinnabar, as in all probability it will, from the large quantities of cinnabar found in the adjacent gravel, it would be a matter of considerable importance, as there is a great consumption of quicksilver in connection with goldmining. No doubt large quantities of mercury could be got by simply putting the richest of the gravel into a retort, and driving the mercury off in the usual way.
Professor Black reports on the ore as follows:—
"This sample of cinnabar, forwarded by Mr Robert Gillies from Waitahuna, contains 76 per cent, of metallic mercury. Three more samples forwarded at different times, and by different parties, averaged page 20 72.33." Professor Black goes on to say :—"This ore is very valuable if it exists in quantity."
The metal is easily freed from the ore by means of simple retorting with lime.
The principal mines of cinnabar are at Almaden, in Spain. There the ore contains 10 per cent. of mercury, and the mines are worked to a depth of 1000 feet, and produce 800 tons per year. Germany produces 350 tons of mercury a year.
Davies on Mining says at page 280 :—"In Peru, mercurial ores have been found in between 40 and 50 places, the product from which is 900 tons a year. In an alluvial deposit near one of the mines, 600 pounds of mercury were taken out of a shaft only 6 feet deep. The alluvial in the neighbourhood seems penetrated with mercury."