408 Transactions. — Q-eology. 



brown and red, and occurs in considerable quantities at some places. It is 

 mentioned by Dr. v. Haast (Jurors' Eep. N.Z. Ex., 1865, p. 257, and Geol. 

 Kep., 1873-74, p. 9) associated with the quartz porphyries of Mount Somers 

 and Snowy Peak. 



Altjminates of Magnesia and Glucina. 

 Spinel, Mg Ak — The occurrence of rubies with garnet and topaz in the 

 alluvium of Waipori, Otago, is meutioned by Dr. Hector (Jurors' Eep. N.Z. 

 Ex., 1865, p. 416). This mineral is also mentioned from Manawatu, 

 Wellington (Col. Mus. and Lab. Eep., v., p. 18) as rhombic dodecahedrons, 

 and nearly opaque. They were not analyzed, and so are very probably 

 garnets. 



Silicates of Glucina, Zirconia, Thoria, and Yttria. 

 Zircon, Zr, Si. — The occurrence of this mineral is mentioned by Dr. 

 Hector (Jurors' Eep. N.Z. Ex., 1865, pp. 417, 438), who says " crystals 

 of zircon were exhibited, in the Museum of the Geological Survey, from 

 Timbril's Gully," and (Trans. N.Z. Inst., vol. ii., p. 371) with platinum 

 and gold in the wash of the south ; and by Dr. v. Haast from the western 

 slopes of the Southern Alps (Geol. Eep., 1870-71, p. 24). In the collection 

 of the Colonial Museum there is a specimen of a biotite rock from Doubtful 

 Inlet, Otago, in which there are numerous minute tetragonal prisms with 

 pyramidal ends of a bright red colour, transparent, which are probably 

 zircons. 



Topaz, 5 'j& Si + (-A1 F 3 + Si F 2 ).— Is mentioned by Dr. Hector at 

 Chatto Creek, Arrow Eiver, and Waipori (Jurors' Eep. N.Z. Ex., 1865, 

 pp. 265, 438) ; and (p. 416) he says, " in collections from the Otago Gold- 

 fields' department were some uncut topazes as large as pigeons' eggs, and 

 of a pure white colour. Several smaller topazes of various colours have 

 lately come into the possession of the Geological Survey of Otago from the 

 neighbourhood of Waipori, where they are found in the alluvium along with 

 rubies, garnets," etc. 



Emerald, Al Si 3 + 3 Gl Si. — Specimens of this mineral have been for- 

 warded from Dusky Sound by Mr. W. Docherty, of which Mr. Skey 

 says : — " This is a somewhat rare mineral collected by Mr. William 

 Docherty, from a vein in the vicinity of Dusky Sound. When tested, 

 it was found to be the mineral beryl, the distinguishing feature of which is 

 the presence therein of the rare metal glucinum (beryllum.) Usually, this 

 is to the extent of 12 to 15 per cent, in specimens of this kind. The 

 mineral is of a full rich green colour, which it owes to the presence of 

 sesquioxide of chrome. It occurs at Dusky Bay, in a pyrrhotiniferous 

 quartz, forming little nests of confusedly crystalline masses having a 

 tendency to assume a tabular form." 



