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Volume 10, 1877
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Art. LXXVII.—Notes on some of the New Zealand Minerals belonging to the Otago. Museum, Dunedin.*

[Read before the Otago Institute, 23rd October, 1877.]

Graphite.—Nelson.

Compact, with lamellar and petaloidal structure; requires purification to render it of commercial value.

Graphite.—Fews Creek; Wakatipu.

Lamellar structure, impure, much contaminated with sesquioxide of iron, which is probably derived from the decomposition of iron pyrites.

Graphite. —Dunstan, Otago.

Rather loose and friable; impure. A sample from Clyde, Dunstan, was analyzed by Mr. Skey, and gave the following results:—

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Water 3.5
Earthy matter 51.1
Carbon 45.4
100.0 (Skey).

Retinite.§—Dunstan.

In massive more or less rounded lumps; colour, shades of brown, ochre, and grey, which are often mingled in irregular wavy streaks; the external surface is somewhat rough and pitted; breaks with a well-marked large conchoidal fracture; brittle; burns readily, with a smoky luminous flame, evolving a somewhat aromatic odour; heated in a closed tube, fuses, gives off white fumes and furnishes a yellow distillate; blackens on the continued application of heat.

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Analysis.
Carbon 75.979
Hydrogen 11.512
Oxygen 12.306
Ash .203
100.000 (Liversidge).

[Footnote] * As in many instances these mineral specimens or other specimens from the same localities have already been determined and reported on by the Geological Survey Department of New Zealand, the previous reports are cited for convenience of reference.—Ed.

[Footnote] † For analysis see Reports N.Z. Exh., 1865, p. 417.

[Footnote] ‡ Rep. Col. Mus. and Lab., 1870, p. 14.

[Footnote] § Rep. N.Z. Exh., 1868, p. 438.

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Retinite.—Bay of Islands.

Found in coal. In colour, brown, almost black, by transmitted light the colour is a rich amber brown. Fracture conchoidal, very brittle; does not fuse readily, burns with a luminous smoky flame, and leaves a very small quantity of white ash.

Bitumen.—Poverty Bay.

The exterior surface is of a brown colour, within it is black; burns with a luminous smoky flame, emitting a bituminous odour; leaves a small quantity of white ash; breaks with conchoidal fracture; very brittle; possesses bituminous odour.

Sulphur.—White Island.*

Massive, of a rich sulphur-yellow colour, with reddish tinge in parts, in places the exterior surface is coated with white earthy matter; small imperfect crystals of sulphur occur in the cavities; contains traces of selenium.

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Analysis.
Sulphur 99.614
Impurity .386
100.000 (Liversidge).

The impurity consists principally of a white clay-like pipeclay.

A second sample yielded the following result:—

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Analysis.
Sulphur 99.554
Foreign matter .446
100.000 (Liversidge).

Sulphur.—White Island.

Very similar to the former.

Sulphur.—White Island.

A loose friable variety of sulphur with a pale greenish tinge of colour.

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Analysis.
Sulphur 98.888
Foreign matter 1.112
100.000 (Liversidge).

The foreign matter consists for the most part of pipeclay-like material.

Calcite.—Dunedin.

In small rhombohedral crystals, of a pale green tint, closely seated together in an amygdaloidal cavity.

[Footnote] * Trans. N. Z. Inst., III., 278.

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Calcite.—Dunedin.

In rhombohedral crystals lining an amygdaloidal cavity. The terminal group of rhombohedral faces (arranged in groups of three) have a bright lustre; but the faces of the prism or elongated rhombohedron have drusy and brown-coloured surfaces.

Calcite.—Chalky Inlet.

A cleavage rhombohedron; opaque white, but almost transparent in parts.

Calcite.—Moeraki.

From a septarian; of a yellow colour; the under surface is studded with dark brown-coloured spots, which are apparently imperfectly-developed rhombohedral crystals. These spots are rich in iron and manganese. Before the blow-pipe the yellow colour is changed to black; due to the presence of iron. One side of the specimen is irregular, from the presence of bold, but imperfectly-defined scalenohedral crystals.

Calcite.—Sunnyside, Dunedin.

Smoky, translucent crystals of calcite, made up of the rhombohedron combined with the scalenohedron. Associated with them are radiate groups of acicular natrolite crystals.

Calcite.—Dunedin.

The crystals are small, fairly well-developed acute rhombohedra, arranged together in a most beautiful little group; the crystals are of a pleasing brown colour, with drusy surfaces. The calcite crystals are seated upon a thin coating of natrolite, which lines the amygdaloidal cavity. On the brown rosette of calcite is seated, in turn, a pretty little group of clear transparent crystals of some zeolite, apparently skolezite.

Calcite.—Dunedin.

In pale yellow transparent rhombohedral crystals; lining a cavity.

Calcite.—Dunedin.

Similar to the above.

Calcite.—Dunedin.

In small white rhombohedral crystals, seated on a pale brown-coloured calcite, lining an amygdaloidal cavity.

Calcite.—Dunedin.

Group of fairly well-developed rhombohedral crystals; pale greenish tint, translucent.

Calcite.—Sunnyside, Dunedin.

Small brown translucent crystals, consisting of the scalenohedron and rhombohedron combined; associated with one of the zeolites. The zeolite fuses easily to a clear glass, without intumescence.

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Calcite.—Dunedin.

In brown transparent crystals, made up of similar forms to the last. Lustre vitreous. Associated with the calcite are radiate groups of natrolite crystals, and both are seated upon a pale blue-coloured film of a minutely crystallized zeolite, which has some of the characters of gismondine.

Calcite.—Dunedin.

In group of translucent pale green-coloured crystals, lining an amygdaloidal cavity.

Calcite.—Dunedin.

A group of brown imperfectly-developed crystals.

Calcite.—Dunedin.

In radiate groups of small crystals, composed of the scalenohedron and rhombohedron combined; well developed, although almost microscopic in size.

Translucent; lustre vitreous; in amygdaloidal cavity. There is also present in the specimen a cast or impression of a radiate group of acicular arragonite crystals.

Calcite.—Dunedin.

A group of clear, transparent, and colourless crystals, with vitreous lustre. The forms are flattened elongated rhombohedra, which penetrate right across the cavity and abut against the opposite side.

Calcite.—Dunedin.

A radiated group of crystals consisting of the scalenohedron and rhombohedron combined.

Arragonite.* —Dunedin.

Filling amygdaloidal cavities in basalt.

Arragonite.—Caversham.

Long blade-like prisms in an amygdaloidal cavity lined with the zeolite natrolite.

Arragonite.—Dunedin.

In radiate rhombic prisms of a pale pink colour, with vitreous lustre. The cavity is lined with small rhombohedral crystals of pale yellow calcite.

Arragonite.—Dunedin.

Beautiful rosettes of pale yellow-coloured prisms with vitreous lustre. The under portions are much charged with iron, and in consequence present a brown colour. Presented by Captain Fraser.

Selenite.—Moeraki.

A clear and transparent form of gypsum, (i.e., hydrous calcium sulphate=Ca SO4, 2H2O); roughly crystallized; valuable for the preparation of various cements.

[Footnote] * Rep. N.Z. Exh., 1865, p. 437.

[Footnote] † Rep. N.Z. Exh., 1865, p. 422, 437.

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Gypsum or Selenite.—Awamoko.

In thin roughly crystallized plates, mixed with black shaly matter.

Gypsum.*—White Island.

Associated with sulphur in thin columnar crystals somewhat interlacing; opaque white; somewhat fibrous in structure.

Gypsum.—Wakatipu.

A white, opaque, mammillated incrusting mass, from a cave at Mr. Nicholas', Lake Wakatipu.

Vivianite.

A small rolled nodule of a dull blue colour, and earthy appearance; breaks with a flat conchoidal fracture; hardness=3; streak pale blue; almost entirely soluble in acid.

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Analysis.
Hygroscopic moisture 3.017 or loss at 100° C.
Combined water 21.425 by difference
Iron protoxide 28.177
" sesquioxide 16.363 Soluble in hydrochloric acid
Phosphoric acid 31.018
100.000 (Liversidge).

Quartz.—Hendon.

White vein quartz, with clear transparent crystals on one surface made up of the hexagonal prism combined with the pyramid. (∞ P, mP.)

Quartz.—Milford Sound.

Translucent white, much fissured, and in consequence almost granular in structure.

Chalcedony.—Moeraki.

Massive; bluish-grey colour; translucent, with small quartz crystals in the cavities.

Chalcedony.—Otepopo.

Mammillated; translucent; grey with yellow patches.

Agate.—Mount Charles, Otago.

A mixture of grey chalcedony and quartz crystals stained with a little hydrated sesquioxide of iron.

Flint.—Moeraki.

Grey, with brown and dark blue-grey streaks, fissured; conchoidal fracture; pitted on the weathered surface, which is grey in colour.

Chert.—Amuri Bluff.

Somewhat chalky appearance, exhibiting bluish and yellowish tints; white in parts. Hardness about 6.5. Effervesces with hydrochloric acid.

[Footnote] * Trans. N.Z. Inst., III, 280.

[Footnote] † Rep. N.Z. Exh., 1865, p. 436.

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Chert.—Waihola.

Of the colour of yellow-ochre; cavities lined with bluish-coloured quartz and chalcedony? The translucent grey portions, when heated in a closed tube, decrepitate somewhat, give off water, a slight white sublimate and fumes of sulphurous acid; does not blacken; the ochre-coloured portions give off water, a slight sublimate similar to the last is formed, and an empyreumatic odour is evolved; the residue blackens (but finally burns to a reddish-brown, due to the presence of iron oxide), and the condensed water has a strongly alkaline reaction, all of which tend to indicate that organic matter is present. The hardness of the ochre-coloured part is greater than that of the grey portion, the former being about 6.5, and the latter not more than about 5.5.

The blue-grey portion appears to be a film of chalcedony (or hyalite) coating small and imperfect quartz crystals.

Carnelian.—Coromandel.

Two specimens of reddish-brown carnelian or chalcedony, but wanting purity of colour and translucency.

Carnelian.—Coromandel.

Colourless, transparent carnelian.

Hardness only about 5.5. Heated in closed tube the specimen gives off a trace of water, having an alkaline reaction, and evolves a faint empyreumatic odour; conchoidal fracture with vitreous lustre.

Flint.—Tapanui.

A brown-coloured water-worn nodule, closely resembling the flint from the chalk of England.

Flint.—Wangarei Heads.

Water-worn nodule, variegated grey and white colour, somewhat fissured. Unlike the chert from Amuri Bluff it does not effervesce with acids.

Chert.—Otago.

Of a pale green colour.

Chert.—Otago.

Possessing an impure lavender colour.

Jasper.—Clutha.

Portion of a waterworn nodule, sliced and polished; of a pale green colour, streaked with darker shades; fissured, showing “faults” which are made plainly visible by the bands of darker colour.

Green Jasper.—Moeraki.

Variegated with reddish-brown streaks; a little chalcedony on one surface. The green colour is mainly due to the presence of protoxide of iron; there is also manganese present in small quantity. On heating in a

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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 redbrown, 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 stalactitic 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 empyreumatic 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 McKerrow.

Massive; cleavage planes fairly well marked.

Hornblende.—West 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.—Lake McKerrow.

Foliated and confused masses of crystals; colour green; lustre not wellmarked.

[Footnote] * Rep. N.Z. Exh., 1865, p. 438.

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Hornblende.—Dunedin.

Portion of an embedded crystal.

Diallage.—Dun Mountain.

In large confused crystals, with well-marked lamellar structure.

Hypersthene.—Warp Point, Kaduku River.

In small confused dark green-coloured crystals.

Chloritic Schist.—Deep Creek, Kakapo Lake.

Composed of green-coloured chlorite in part, passing into fibrous, wavy, and interlacing crystals of hornblende.

Olivine.* —Dunedin.

Brown-coloured embedded grains, possessing a green shade; fragmentary or imperfectly-developed crystals.

Steatite.—Nelson.

Massive, with somewhat foliated structure; greenish in colour. Should be of commercial value for the manufacture of gas-burners, the preparation of French chalk, etc.

Serpentine.—Windley Creek.

Massive; of a dull green colour; translucent. This is the mineral serpentine, and not the rock which is known by that name.

Marmolite. —Anita Bay.

A foliated form of serpentine, which resembles nephrite (the mineral known as jade or greenstone, the pounamu of the Maoris) in some respects; it is, however, at once distinguished by its softness.

Green in colour, and possesses a hardness of about 4.

Marmolite?§ (Steatite?).

Pale green folia, on serpentine, containing hypersthene; greasy feel; hardness about 3.5; rather brittle.

Chloropal.—Presented by Captain Fraser.

Of a yellowish-green colour; somewhat foliated cone-in-cone structure; sectile; soft; easily polished, even by rubbing with the thumb; adheres slightly to tongue: when immersed in water gives off air-bubbles, and becomes translucent.

Before the blow-pipe does not decrepitate; blackens immediately, and fuses with difficulty in thin edges, with slight intumescence, to a black glassy slag.

Mica (Muscovite).—Charleston, West Coast.

In large plates; brown with greenish shades and metallic lustre.

[Footnote] * Contains chromium, Rep. N.Z. Exh., p. 413.

[Footnote] † Geol. Reports.

[Footnote] ‡ Rep. N.Z. Exh., 1865, p. 412.

[Footnote] § Rep. N.Z. Exh., 1865, p. 412.

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Analysis.
Silica 45.007
Iron sesquioxide 4.138
Alumina 37.144
Potash 10.049
Lime .517
Magnesia 1.286
Undetermined constituents, water, soda, etc. 1.859
100.000 (Liversiage).

Presented by Mr. C. H. Hardy.

Mica.—Dusky Bay.

In medium-sized plates; brown in colour; associated with quartz and a little decomposed garnet.

Felspar (Albite)*—George Sound.

Fairly well-marked cleavage planes, white, small red stains on weathered surface; fuses more easily than orthoclase.

Orthoclase.—Paterson Inlet.

Massive, presenting large cleavage planes, of the ordinary pale pink-brown tint. Attached to one end of specimen is some graphic granite or pegmatite.

Presented by Mr. Kinnear.

Orthoclase.—Cooper Bay.

Similar to the last.

Presented by Mr. Kinnear.

Orthoclase.—Cooper Bay.

Rolled specimens, contain embedded quartz crystals.

Granite.—Milford Sound.

Labelled “lithia mica.†”

A mixture of white felspar and black mica. No lithia could be detected in this specimen; both the mica and felspar appeared to be free from it, according to qualitative tests; therefore, to make doubly sure, the alkalies in both the mica and the felspar were separated and again examined for lithium, but with negative results.

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Alkalies in the Mica.
Potash 3.823
Soda 2.136
5.959 per cent. (Liversidge).

[Footnote] * Rep. N.Z. Exh., 1865, 437.

[Footnote] † Lithia mica occurs in marble at Thomson Sound. Rep. N.Z. Exh., 1865, 437.

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The mica was not perfectly pure; it was found difficult to separate it completely from the other constituents of the rock; the difficulty was mainly due to the smallness of the quantity at my disposal.

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Alkalies in Felspar (Albite)
Potash 1.071
Soda 5.590
6.661 per cent. (Liversidge).

Garnet.—Breaksea Sound.

An embedded crystal (the rhombic dodecahedron) broken across. The matrix is syenite, having the wavy foliated structure of gneiss. Immediately around the garnet the hornblende is almost entirely absent, which causes that part of the matrix to be much lighter in colour, and consequently the garnet is shown up to much greater advantage.

It is highly probable that the hornblende and garnet are not very dissimilar in chemical composition, and that when the rock underwent metamorphism, and its constituents were free to re-arrange themselves, the garnet “nucleus,” or centre of crystallization, had the power to abstract and build up certain of the rock constituents which would have otherwise assumed the form of hornblende. Hence the probable reason of the absence of hornblende in the immediate neighbourhood of the garnet. It would be very interesting to put this suggestion to the proof by chemical analysis, should additional specimens be obtainable.

Limestone.*—Crooked Arm, West Coast.—(Labelled “Cipillino.”) A white saccharoid limestone or marble, containing small crystals of brown mica, a little quartz, and a few scales of graphite.

The variety of marble known as cipillino contains talc or chlorite, hence it is marked by green-coloured streaks and veins.

This specimen cannot therefore be classified with it.

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Analysis.
Carbonic acid 38.284
Iron sesquioxide and alumina 1.253
Lime 48.269
Magnesia 402
Mica, silica, etc, insoluble in acid 9.459
Undetermined constituents 2.333
100.000 (Liversidge).

Halloysite.—Water of Leith, Dunedin.

An opaque white earthy substance, soft and soapy; associated with it is a little black halloysite; when immersed in water it gives off air bubbles

[Footnote] * Report West Coast Expedition, Otago Gazette, 1863, 459.

[Footnote] † Rep. N.Z. Exh., 1865, 438.

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rapidly, accompanied by a singing sound; falls to pieces, and becomes translucent on the thin edges; breaks with a conchoidal fracture; adheres strongly to the tongue; yields to the thumb nail and affords a shining streak; possesses an earthy smell.

Schrötterite?—Malvern Hills. (Labelled “Pinite.”)

In rounded wax-like masses, filling the cavities of an amygdaloidal trachyte (?) rock, and as a mammillated incrustation upon its surface; green, grey, and white; hardness about 3.5; streak white, rather tough; breaks into more or less conchoidal flakes; translucent; waxy lustre. Before the blow-pipe it becomes white and opaque, and much harder (thus differing from the ordinary behaviour of both pinite and allophane), 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 closed tubes.

Zeolites.*
Natrolite.—Sunnyside, Dunedin.

In radiated tufts of white acicular crystals, and coating a hemispherical concretion of ferruginous calcite.

Presented by Mr. D. Millar.

Natrolite.

In beautiful radiated tufts of acicular crystals.

Natrolite.—Dunedin.

Natrolite.—Dunedin.

Natrolite.—Dunedin.

Associated with an incrustation of siderite or iron carbonate.

Natrolite.—Dunedin.

Compact form, exhibiting radiate structure; lining amygdaloidal cavities in basalt.

Natrolite.—Dunedin.

Forming a thin investing coating on interior of amygdaloidal cavity.

Stilbite?—Dunedin.

In the cavities of these specimens are minute detached crystals of one of the zeolites. The form appears to be that of the rhombic prism capped with the pyramid; this is a combination often assumed by stilbite, and in addition the little crystals possess a very high lustre, not unlike that of stilbite; moreover, they behave like that mineral before the blow-pipe, hence they probably belong to the same species.

Not sufficient to permit an analysis to be made without destroying the specimens completely.

[Footnote] * Rep. N.Z. Exh., 1865, p. 438.

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Metalliferous Minerals.

Platinum.*—Southland.

In the form of small flattened grains.

On account of the smallness of the specimen, I did not think it advisable to use any portion of it for chemical examination; and, moreover, Professor Black has published the results of his examination of a sample from the Bluff, which is apparently very similar to this specimen.

He states—“It consisted of from 35 to 42 per cent. of platinum (black or magnetic oxide of iron not estimated), and an alloy of platinum, osmium, and iridium.”—Vide Geology of Otago, p. 149.

Ariferous Quartz.—Taieri Goldfield.

From the prospectors' reef in a gully leading into Frazer's Gully.

Thickness of reef, 3 feet.

Contains visible gold.

Auriferous Quartz.—Adelaide Reef, Taieri.

Vein-quartz, stained with iron oxide. But a small quantity of visible gold present.

Auriferous Quartz.—Adelaide Reef, Taieri.

White vein-quartz.

Auriferous Quartz.—Blacksmith's Gully.

Vein-quartz, containing visible gold; from surface.

Auriferous Quartz.—Sorensin's Old Reef, Skippers.

Of a bluish colour, rich in visible gold.

Auriferous Quartz.—Nevis River.

Four specimens of more or less crystallized quartz.

Auriferous Quartz.—Serpentine River.

Contains a small quantity of visible gold.

Auriferous Quartz.—Pleasant River.

Contains visible gold, especially near the talcose vein.

Auriferous Quartz.—Adelaide Reef.

Two specimens, containing but a small quantity of visible gold.

Auriferous Quartz.—Hendon Reef.

Brownish-coloured hornstone-like quartz, marked with grey streaks; contains visible gold.

Auriferous Quartz.—Tuapeka (from the Blue Spur.)

A mass of quartz, schistose, and other pebbles, mixed with much water-worn shotty gold, cemented together by a chloritic base.

Presented by Mr. Nichol.

[Footnote] * 4th Lab. Rep., 1869, No. 486.

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In the form of minute globules, mainly more or less hidden away in the crevices. The dark veins contain, in addition to mercury, both copper and sulphur.

Cinnabar.*—Waipori.

In the form of rolled fragments, which show traces of crystallization in the cavities. A very rich and highly valuable ore of mercury.

Cinnabar.—Bay of Islands.

Earthy and associated with petroleum.

Native Copper.—Moke Creek. Presented by Mr. J. S. Worthington. Rolled nodule, somewhat cavernous, more or less coated with cuprite (the red oxide) and malachite (hydrous green carbonate of copper); associated with them are adherent fragments of quartz evidently a portion of the veinstuff.

Cuprite.—Dun Mountain.

Impure, coated in part with green carbonate of copper. When pure this ore contains 88.8 per cent. of metallic copper.

Bornite.—Dunstan.

In micaceous quartz with a somewhat schistose structure, mixed with a little common copper pyrites and green carbonate. One portion is from a rolled nodule. This variety of copper pyrites, when pure, contains about 70.1 per cent. metallic copper.

Chrysocolla.—Nelson.

A specimen of the impure green hydrated silicate of copper.

Chalcopyrite.—Moke Creek.

The common variety of copper pyrites.

Mispickel.—Collingwood, Nelson.

In small but fairly well-formed crystals. This mineral is an arsenical sulphide of iron.

Antimonite.—Union Jack Reef, Mullocky Gully.

Massive crystallized sulphide of antimony, associated with cervantite, the yellow oxide of antimony, and some quartz.

Wad.§—Thames Goldfield.

An impure earthy form of manganese binoxide; associated with quartz.

Rhodonite.—Dunstan.

A massive form of the silicate of manganese, mixed with a little binoxide of manganese. This mineral forms a very beautiful ornamental stone when cut and polished.

[Footnote] * Rep. N. Z. Exh., 1865, p. 404.

[Footnote] † And others, Rep. N. Z. Exh., p. 405.

[Footnote] ‡ Rep. N.Z. Exh., p. 404.

[Footnote] § Geol. Reports, 1870, p. 87.

[Footnote] ‖ Rep. N.Z. Exh., p. 413.

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Scheelite.*—Blackburn.

A massive specimen of calcium tungstate in rolled nodules; contains a little quartz.

Scheelite.—Lake Wakatipu.

Very much the same as the last.

Galena.—Tokomairiro.

This is the common ore of lead, a compound of lead and sulphur; associated with quartz.

Presented by Mr. Gillies.

Galena.—Wangapeka.

Rolled nodule of quartz, containing veins of galena.

Galena.—Nelson.

Associated with quartz.

Magnetite.—Dunstan.

A rolled nodule of the magnetic oxide of iron (Fe3 O4), containing quartz.

Magnetite.—Maori Point, Shotover.

Massive, with a granular structure. Stained with green carbonate of copper.

Magnetic Iron Sand.—Awamoko Creek, Marawhenua Goldfield.

The specimen consists principally of rolled grains of magnetite and of titaniferous iron; associated with them are a few zircons (hyacinth), a little gold, brown hematite, a little quartz sand, and pieces of iron from tools.

Magnetite.—Nelson.

Massive, impure; stained in places with green carbonate of copper.

Associated with it is a compound silicate of iron, lime, magnesia, potash, and soda.

Specular Hematite.—Longwood Mountains.

In small lamellar and granular masses, embedded in quartz.

Red Hematite.—D'Urville Island.

Massive; of very good quality.

Red Hematite.—Horseshoe Bush.

A botryoidal concretion of sand, cemented together by red oxide of iron.

Brown Hematite.—Dunstan.

A hollow nodule of the variety of iron ore known as limonite. Of very good quality; when fairly pure this ore contains some 55 per cent. of metallic iron; the red variety of hematite may contain as much as 70 per cent.; and magnetite, which is the richest, may yield 72 per cent. of iron.

[Footnote] * Rep. N.Z. Exh., p. 414.

[Footnote] † 5th Lab. Rep., 1870, No. 836.

[Footnote] ‡ And others, Rep. N.Z. Exh., 1865, p. 407.

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Metallic iron.
When chemically pure, Brown Hematite contains 59.39
""" Red "" 70.03
""" Magnetite "" 72.40

Brown Hematite.—Lansdowne, Port Molyneux.

Exhibiting a concretionary and cavernous structure. Labelled 65 per cent. of iron.

Siderite.*—Dunedin.

Groups of small brown-coloured rhombohedral crystals of the carbonate of iron; the rhombohedra are piled up into little columns. Lining cavity in basalt.

Magnesian Ironstone.—Clutha.

A rolled nodule. Hardness about 6; tough; somewhat splintery fracture. Contains some manganese. Effervesces slightly with boiling hydrochloric acid.

Dendritic Iron Markings.—North-East Valley.

Presented by Mr. R. Hempseed.

Chromite.—Moke Creek, Queenstown.

Of rich quality; granular in structure; incrusted in part with chrome ochre.

Chromite.—Dun Mountain.

Of rich quality; granular structure; attached on one side is a little serpentine.

Chromite.—Milford Sound.

Rich quality; a rolled nodule; granular structure; associated with a little steatite.

Iron Pyrites.—Shotover.

In well-developed cubes, embedded in chlorite schist.

Iron Pyrites.—Maori Point, Wakatipu.

In large cubes embedded in a similar chlorite schist to the above.

Native silver.—Kawaru.

Small specimen; tarnished with (Ag2 S) coating of sulphide.

N.B.—(Should have followed native platinum.)

Presented by Dr. Alexander.

Miscellaneous.

Quartzite in Basalt.—Near Mount Livingstone.

An angular fragment of quartzite, embedded in a porphyritic basalt.

To determine whether the enclosed fragment consisted of pure silica, the following estimates were made:—

Silica 85.030
Sesquioxides of iron and alumina 4.878

[Footnote] * Rep. N.Z. Exh., p. 436.

[Footnote] † Rep. N.Z. Exh., p. 410.

– 505 –

From which it will appear that the enclosed fragment cannot be regarded as quartz but rather as quartzite; it is probably a portion of some sedimentary rock which has been metamorphosed by the action of the fluid basalt.

Taranakite.*—Taranaki.

[Footnote] * Rep. N.Z. Exh., 1865, p. 423.