230 NOTES ON SOME ROCKS AND MINERALS FROM NEW GUINEA, &C. 
apparently from a coral reef; and others of a grey colour, one of 
which, evidently coral reef debris, enclosed rolled white q uartz 
and other pebbles. 
DarNLEY ISLAND. 
With the above are a few specimens from Darnley Island. 
car. 
fragment of a buff coloured tufaceous rock, containing a consider- 
able amount of carbonate of lime in the form of recognisable 
fragments, but most of it disseminated in fine grains mixed with 
iron oxide 
On treating a fragment of the rock with hydrochloric acid, it 
dissolves in great part, and leaves a grey c ae residue w 
under the microscope, has the appearance o volcanic ash ; 
a of green augite, brown and sclourtees: crystals, being 
abundan 
Baxter River (New Gurxea). 
Rolled nodules of white vein quartz, with a pebble of grey 
coloured chalcedonic quartz ; of a basalt and of a dark grey felsitic 
rock ; another specimen is a pebble of a dark coloured very tough 
diabase rock. 
Concretions of impure red hematite, like those occurring in the 
Wianamatta shale, and like them probably derived from a shale, 
Various specimens of alluvial deposits obtained from the river 
banks, passing from loose grey and black soils to stiff and 
tenacious red clays. One of these is laminated like a shale and 
contains mica scales; it is probably the source of the ironstone 
concretions. 
The scales of mica sont indicate the presence of older 
crystalline rocks in the in 
Obtained from 35 miles ne ‘the river. Some of the soils are 
very full of vegetable matter, and should be very fertile. 
Bole.—Of a red colour, also variegated red and white ; adheres 
to the tongue, and scales off in fragment ts with a conchoidal frac- 
ture ; gives shining streak, and is subtranslucent. Falls to pieces — 
when placed in water with a slight crackling sound, and emits a 
rapid cic of minute air bubbles. 
Chrysolite.—Small pale green rolled pebbles, fairly transparent; 
all external crystalline form worn off. Collected by the Rev. G. 
eee in Sam 
Aragonite.—In the form of stalactites from Tanna. 
Sulphur, sulphates, and similar voleanic minerals, are common 
in Tanna and some of the other islands. 
As a whole, the variety of minerals at present obtained from New 
Guinea and the islands is very limited. 
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