Skey and McKay. — On Minerals from Stewart Island. 421 



These schistose and gneissic rocks are here, on the shore of 

 the harbour, divided into two outcrops, as seen in section. 

 They cannot be easily traced to the north, in which direction 

 their exposures trend, although the strike of their lamination 

 is between W.N.W. and N.W. South of the Tin Range there 

 is a table-land about 7oOft. above the sea, ending in a fringe 

 of broken hilly country on the north side of the harbour. In 

 the direct line of the crest of the Tin Range I sank a hole to 

 the bed-rock, and found the rock pure mica, and so soft that 

 for 18in. or 2ft. it was easily dug into with the shovel. But 

 more to the north and west of this, at the same and higher 

 elevations, the rock is granite — which, however, disappears at 

 1,000ft. on the west slope of the Tin Range — and mica and 

 quartz rock, forming the higher part of the range. 



The tin-bearing bands are segregations of quartz in the 

 mica rock, which are traceable in the fashion of small reefs or 

 leaders, sometimes continuously for a considerable distance. 



The particular segregation-band in which tin-ore has as 

 yet been found contains, besides the tin-ore, considerable 

 quantities of wolfram, and at places a form of topaz is plenti- 

 ful. The form of spinel mentioned in Mr. Skey's paper 

 comes from the tin-deposit on the extreme southern end of 

 the range, as does the peculiar blue variety of zinc-blende 

 determined by him. 



The sample of fluor-spar tested in the Laboratory was given 

 me by a prospector, who stated that it came from Doughboy 

 Bay ; and I should say that its occurrence there is not im- 

 probable, seeing that the radical of the mineral is found in 

 the topaz mineral obtained by myself from the Tin Range, 



Topaz- and garnet-sand is plentiful in the alluvial deposits 

 of the low ground within the watersheds of Pegasus and 

 Smith's Creek, and is a great annoyance in collecting the 

 tin-sands, more especially the grey topaz-sand. I have 

 marked on the plan the areas of alluvial deposit over which 

 stream-tin had been found at the time I left the Port Pegasus 

 district. I am not aware that any fresh areas had been dis- 

 covered, and none have been reported since. 



Assay of Copimr-orc. 



Assay-office, Bank of Australasia. 



Nos. 1, 2, 3, and 4: Mixed, principally copper-pyrites. — 

 400gr. gave 74gr. of copper, or 18 per cent. 



No. 5 : Pyrites, with a little green pyrites. — Not enough 

 in quantity to assay. 



No. 6 : Pyrites and black oxide. — 400gr. gave lOOgr. of 

 copper, or 25 per cent. 



Nos. 7 and 8.— Ditto. 



