402 Transactions.— Geology. 
intersected by numerous small white veins. Readily decomposed by H. 
Cl. at a temperature of 212° Fah.; lost 18 per cent. water, but as it is 
very probable this is in greater part or altogether constitutional along with 
that requiring a higher temperature for its expulsion, the whole of the 
water present in the stone is entered in the appended analysis under one 
head :— 
Silica .. cs s E .... 88:82 
Alumina xe is sa vi 25:17 
Oxides of iron >š ee 2x = ee 
Lime .. t : 3:65 
Magnesia 8:27 
Alkalies 2-03 
Water .. Du at ss y 22-76 
Carbonaceous matter A .. traces 
100-00 
Schrétterite, Ag Si + 8 H.—Professor Liversidge (Trans. N.Z. Inst., 
vol. x., p. 500) mentions a mineral from the Malvern Hills, Canterbury, 
which is probably sehrótterite. His description is as follows :—** In rounded 
wax-like masses, filling the cavities of an amygdaloidal trachyte (?) rock, and 
has a mammillated incrustation upon its surface ; green, grey, and white ; 
hardness about 8:5; streak, white; rather tough; breaks into more or 
less conchoidal flakes ; translucent; waxy lustre. Before the blowpipe it 
becomes white and opaque and much harder, intumesces slightly and tinges 
the flame green ; affords deep blue when ignited with cobalt nitrate ; does 
not gelatinize with hydrochloric acid, but granular silica is thrown down : 
gives off much water when heated in a closed tube.’ 
Pimelite, 9 A] Si + 8 Mg Si + 10 H.— The occurrence of this mineral 
filling cavities in amygdaloidal rocks, at Malvern Hills, Clent Hills, ete., is 
mentioned by Dr. v. Haast (Jurors’ Rep. N.Z. Ex., 1865, p. 257). 
Idocrase (Vesuvianite), 8 (Ca, Mg)? Si+ 2 ‘Al Bi ?.— This mineral occurs 
as dirty green, fluted, prismatic crystals, in quartz associated with the 
crystalline rocks of Dusky Sound; specimens having been forwarded by 
Mr. W. Docherty. The larger crystals have a resinous lustre and the 
smaller ones, which are of a brighter green, are more pellucid. 
Epidote, 2 (Ad, Ee) Si * + 8 Ca Si. —The occurrence of this mineral in 
gneiss granite and granulite of the West Coast is mentioned by Dr. Hector 
(Jurors’ Rep. N.Z. Ex., 1865, p. 266) and by Dr. v. Haast in the diorites of 
Mt. Torlesse range (Jurors' Rep. N.Z. Ex., 1865, p. 257) and in the 
melaphyres of the Mt. Somers district (Geol. Rep., 1878-74, p. 9). A 
massive form from Wairarapa, Wellington, of a greenish-grey colour, is 
also in the collection of the Colonial Museum, Before the blowpipe it 
