On the Occurrence of Fluor-spar at the Bâton Goldfields.

Transactions and Proceedings of the Royal Society of New Zealand, Volume 22, 1889, Page 521

4. “On the Occurrence of Fluor-spar at the Bâton Gold-fields,” by J. Park, F.G.S. Abstract. In this paper the author describes a large deposit of fluor-spar recently discovered at the Bâton. Mr. A. Thomson, who discovered the mineral, took it for scheelite; but Mr. Skey proved it to be fluate of lime. The main outcrop of this interesting mineral is situated on the north face of Thomson's Hill, about half a mile from the saddle on the road from the Bâton to the Wangapeka. It occurs close to the point of contact between the crystalline limestone and granite, and measures from 30ft. to 35ft. in width, and from 50ft. to 60ft. in length, forming a rocky spur running parallel with the outcrop of the limestone and associated micaschist and hornblende-gneiss. Following up a small stream falling into McRae's Creek, a branch of the Wangapeka, the fluor-spar can be traced by loose blocks on the surface a further distance of 20 chains. It is also abundant at the limestone caves near the source of this stream, being there associated with masses of barytas, hæmatite, and quartz-crystals. The main mass of the fluorite is granular, but it also occurs crystalline. Its colour is generally white and pale-green. This is the first discovery of this mineral in New Zealand; but, apart from the scientific interest attached to this, its occurrence has an important bearing upon the probable mineral resources of this district. Fluor-spar is constantly associated with lead and tin in all parts of Europe and America, and in the north of England it forms the gangue of the lead-veins intersecting the carboniferous strata. During the past two years a number of small veins of argentiferous galena have been found at the Owen and Wangapeka goldfields, and, judging from the presence of the fluorite, Mr. Park considers there is a strong probability that the veins found at the Bâton would be of a workable and permanent character, and for this reason he urges that the line of outcrop, the limestone caves, and, in fact, the whole of Thomson's Hill, should be thoroughly prospected for ore-deposits. At the same time, samples of all the minerals associated with the fluorite should be tested for lead, silver, and tin, and other precious minerals usually accompanying that mineral. Fluor-spar is a valuable flux for the reduction of refractory ores, and has been used for this purpose from the earliest times. It is also used for the manufacture of hydrofluoric acid, and as a glaze for pottery.

Sir James Hector considered the presence of fluate of lime a valuable indication that the agencies which had produced deposits of metallic ores had been in operation in the locality. Everything was tending to prove the correctness of the surmise he had frequently ventured, that the northwest district of Nelson would prove one of the richest mineral districts in New Zealand.