496 Transactions.— Geology. 
closed tube it decrepitates slightly, blackens and gives off water having an 
alkaline reaction; there is also a slight empyreumatic odour evolved. 
Pitch Opal.—Dunstan. 
Brown, variegated, light and dark shades. Hardness about 6. When 
heated in closed tube gives off water, blackens and emits empyreumatic 
odour; the condensed water has an acid reaction, and on evaporation 
leaves a carbonaceous residue which blackens on ignition; breaks with a 
well-marked conchoidal fracture. Contains iron. 
Opal Jasper.—Near Dunedin. 
A prettily marked ornamental stone, the predominant colours bieng red- 
brown, blue-grey, and opal-white. Hardness about 6. 
Hyalite.—bell Hill, Dunedin. 
Mammillated, colourless ; opaque white in part, lining cavity in vesicular 
grey trachyte. 
Quartzite. 
An altered or metamorphosed sandstone, containing fragment of fossil. 
Siliceous Sinter.—Hot Springs, Waikato. 
In stalactitie forms ; opaque white; somewhat tender and friable; when 
heated in closed tube, gives off water having a neutral or but faintly 
acid reaction, also emits a slight empyreumatie odour; cracks and breaks up 
into small fragments. This deposit, in common with other similar ones, 
does not consist of pure silica; but contains some alumina, iron, lime, 
alkalies, etc. 
Jasper.—Clutha, Dunstan. 
Rolled nodule, dark reddish brown with veins of white quartz. 
Jasper.—Clutha. 
Very impure. 
Hornblende.*—Lake MeKerrow. 
Massive; cleavage planes fairly well marked. 
Hornblende.—W est Coast. 
Massive; large confused crystals; greenish-black colour. 
Hornblende—Kakanui Mountains. 
Fragment of a large crystal ; well-marked cleavage planes ; black. 
Hornblende.—Dun Mountain. 
Labelled ** amorphous hornblende," shows a jointed structure; breaks 
with a subconchoidal fracture ; has a somewhat greasy feel like serpentine. 
Diallage.—l;ake McKerrow. 
. Foliated and confused masses of crystals; colour green; lustre not well- 
marked. : 
AM 
* Rep. N.Z. Exh., 1865, p. 438. 
