Cox. — On the Mineralogy of Neio Zealand. 



421 



The various oxides of tungsten also afford excellent pigments, and Mr. 

 Skey discovered as early as 1863 that in many cases it could be used as a 

 substitute for tin, notably in the manufacture of Purple of Cassius. The 

 black oxide of tungsten has been proposed as a substitute for blacklead. 

 From its weight, this mineral is frequently found as an associate of gold in 

 alluvial workings, and is known by the diggers as " White Maori." 



Molybdenum. 



Molybdenite, Mo". — Specimens of this mineral occurring as flakes in 

 a gneiss rock from Dusky Sound, were forwarded by Mr. W. Docherty for 

 identification early in 1880, but very little of it has as yet been found. 



It is used for the preparation of blue carmine for colouring porcelain. 



Wulfenite, Pb Mo. — A specimen of this mineral is in the Museum 

 labelled as coming from the Dun Mountain, but I am unable to find any 

 account of how it was received. It was called Mimetesite. 



It occurs as crystals of a flat tabular form, belonging to the Tetragonal 

 System, which are sometimes hollow. 



consisting of (1) ooP,OP ; (2) i P,OP ; (3) ooPoo , OP, i P. 



In colour it varies from wax-yellow to greyish-yellow ; it has a hard- 

 ness of about 3. Yields a metallic bead of lead on charcoal, decrepitates 

 violently and colours a bead of phosphoric acid greenish blue. Its occurrence 

 is interesting, this being the first mention of it in New Zealand. 



Cheomium. 



Chromite (Fe, Mg) (^^ ,j\!i=(EO,E203). — This mineral which consists 

 essentially of a combination of ferrous oxide and chromic oxide with vari- 

 able quantities of magnesic oxide, alumina and silica, is largely represented 

 in New Zealand. It has chiefly been found in the District of Nelson, where 

 at the Dun Mountain it was for sometime extensively worked, about 5,000 

 tons of the ore having been exported. It was first brought into notice by 

 Mr. T. E. Hacket who also in 1861 opened a mine in Aniseed Valley in the 

 same district (Jurors' Eep. N.Z. Ex., 1865, p. 18). It occiu^s in various 

 forms throughout what is known as the mineral belt of Nelson, a band of 

 serpentinous and olivine rocks, which has been traced through the country 

 from D'Urville Island to Little Ben Nevis, and also occurs as an isolated 

 block in the Eed Hills. 



