Cox.—On the Mineralogy of New Zealand. 409 
I have since examined these specimens, and find the following sections 
of crystals, which confirm Mr. Skey's determination :— 
The hardness of the mineral is about 7, and it occurs in the more 
quartzoze portions of a syenitic gneiss, associated with garnets, pyrrhotine 
and chrome mica, as other accessory minerals. | ; 
Tourmaline, n R Si + R? Si, is mentioned by Dr. Hector in the granito 
and gneiss of the West Coast (Jurors’ Rep. N.Z. Ex., 1865, p. 266) ; by 
Dr. v. Haast, in granite, at Mosquito Hill on the West Coast (Jurors’ Rep. 
N.Z. Ex., 1865, p. 257), and by myself in micaceous and hornblende 
schists at Resolution Island (Geol. Rep., 1874-76, p. 31). There are some 
very fine specimens of schorl in chlorite schist, from Collingwood, in the 
collection of the Colonial Museum, arranged as long, black, striated prisms 
in broken strings which radiate from a centre ; they vary from a sixteenth 
of an inch to a quarter of an inch in diameter. Some very beautiful little 
acicular crystals in quartz, from Bedstead Gully, Collingwood, are also in 
the collection; they are of a deep black colour, and red by transmitted light. 
A blackish green variety also occurs in the granite of Tata Island, N elson. 
Arr, XLVIIL.—On a new Mineral belonging to the Serpentine Group. 
By S. Hersert Cox, F.C.S., F.G.S., Assistant Geologist & Inspector of Mines. 
(Read before the Wellington Philosophical Society, 21st October, 1882.) 
Hectorite-—This mineral is described (Col. Mus. and Lab. Rep. xv.) as 
` an altered form of augite, but is more nearly allied to the hydrous silicate of 
the Serpentine Group. As, however, it does not correspond in composition 
with any described mineral, I have given it the name of Hectorite. 
Its composition, as determined xnl . Skey, is— 
Silica © x è vi 51-89 
Ferrous oxide x cs ap Sh .. 1846 
Al 3 ri ie rà ce Wi 
TR oxide 
ese mI 
Lime og 1:99 
Magnesia .. ^ a ca $a 18:94 
Water eed a id à vd v" CIS 
