Cox. — On the Mineralogy of New Zealand. 365 



During the same year another sample of graphite was forwarded by Mr. 

 Beere from the vicinity of Wellington, in which the percentage of carbon 

 was 66-71 ; and Mr. P. C. Cheal also forwarded a very pure sample of 

 graphite from Waiokura Creek, Waimate, Taranaki, the specimen having 

 been found in the bed of a creek. In 1879 Mr. W. Docherty forwarded 

 specimens of mica schist from Dusky Sound, in which scales of graphite 

 were found ; and in 1880 Mr. C. W. Tripp sent samples of graphite slate 

 from the Orari Gorge, which contained 20*62 per cent, of carbon. 



The only samples of this mineral which merit special description are 

 those from Pakawau, Mount Potts, and Waiokura Creek. 



Graphite. — Pakawau. Compact, with lamellar and petaloidal structure ; 

 requires purification to render it of commercial value (Liversidge, Trans. 

 N.Z. Inst., vol. x., p. 490) ; it is more or less schistose, and varies a good 

 deal as regards purity. 



Graphite. — Mt. Potts. Finely laminated ; black and shining ; powder 

 soft, soiling the fingers ; hardness about 1, but including small grains which 

 are harder. Does not feel greasy to the touch. Appears to be an interme- 

 diate form between anthracite and graphite. 



Graphite. — Waiokura Creek. A solid compact homogeneous form, 

 separated in distinct lamina? about T T -g- inch thick with siliceous partings at 

 places. Hardness a little over 1. Colour iron-black with black and 

 shining streaks. Mark on paper corresponds with H. pencil. Has only 

 been found as isolated boulders, the enclosing rock being unknown. It is 

 an extremely valuable form of this mineral. 



Coal. — This mineral is widely distributed throughout New Zealand, but 

 samples from different localities vary greatly in their composition and value 

 as fuel. In 1866 Dr. Hector (First General Coal Keport) divided these 

 into Hydrous and Anhydrous coals, or those which still contain a large 

 percentage of water chemically combined with them, and those which we 

 may assume to have been deprived of that water by a chemical change, 

 which, in some cases, may have been induced by causes operating feebly 

 throughout lengthened periods, or, in others, has been rapidly effected on 

 more modern deposits of carbon, under circumstances which favoured a 

 more energetic action. The large number of analyses which were subse- 

 quently made of the different classes of coals, together with a careful study 

 of their prevailing characteristics, rendered it necessary to further subdivide 

 them, and in 1872 Dr. Hector (Geological Eeports, 1871-72, p. 172) pro- 

 posed the following classification, which has proved so satisfactory that I 

 cannot do better than adopt it in my present paper : — 



I. Hydrous (coal containing 10 to 20 per cent, of permanent water.) 



a. Lignite. — Shows distinct woody structure ; laminated or shows that 

 structure on desiccation ; very absorbent of water. 



