Saturday, September 24, 2011

Australian Journal of Mineralogy Volume 4 Number 2

A New England Region Special Issue

Cover Photograph: Molybdenite with Quartz, Kingsgate, Specimen: NSW Department of Mineral Resources, Size: 10cm high, Photo: D Barnes

Tin-Bearing Minerals
L Lawrence

Several tin-bearing minerals occur in the New England district, with cassiterite by far the most important commercially and mineralogically.

Tungsten-Bearing Minerals
L Lawrence

Four primary tungsten minerals occur in the New England district, wolframite, scheelite, hubnerite and tungstenite, with the first two constituting commercial ores.

Molybdenite, Bismuth and Associated Minerals
L Lawrence

Molybdenite, with or without bismuth and associated minerals, is widespread in the New England district, being derived from the high silica granites and their quartose derivatives. It is found at many localities especially in the northern half of New England.

Antimony Minerals
G Sutherland

Stibnite (Sb2S3), the essential antimony ore, is found at many localities in the New England region though two areas, Hillgrove and Taylor's Arm, are most important.

Gold, Sulphides and other Primary Minerals
L Lawrence

The New England region has produced gold, base metals with silver and several other metallic and non-metallic minerals including some quite rare species. Apart from quartz, few of these are as crystals, but other features such as only recorded Australian occurrence, microtextures or paragenetic association make them mineralogically significant.

Manganese Minerals from the Southern New England District
M Goodwin

There are numerous occurrences of manganese minerals in the southern portion of the New England district, many of which were once mined on a small scale. Since 1960, the area has become a major world producer of the manganese silicate rhodonite, which is used as a semi-precious gem and ornamental stone.

Oxidised Minerals from the New England Region
P Williams

By way of comparison with the renowned primary mineralization of the New England region, occurrences of secondary minerals are not particularly noteworthy. This is no doubt a reflection of the weathering history of the much younger New England region in relation, say, to the Broken Hill Block. However, there are some particular occurrences of oxidised minerals which, if not so remarkable as specimens, are of interest because of their rarity, or for their scientific importance.

Gemstones of New England
G Webb and L Sutherland

The New England area is unique in Australia for the quality, quantity and variety of its gem minerals. Diamond, sapphire, beryl, topaz, quartz, garnet, zircon, feldspar, rhodonite, nephrite, peridot and fluorite form an impressive array from one area.

Zeolites and Associated Minerals from the New England Region
B England

There has been a long history of volcanism in eastern Australia since the Carboniferous Period, associated with former active plate margins as well as intraplate events which occurred during the break-up of the Gondwana supercontinent. As the Australian Plate evolved, basaltic eruptions became increasingly more widespread as rifting and sea-floor spreading developed along its margins. This left a legacy of highly suitable hot rocks for the development of zeolite mineralisation, including extensive areas of Tertiary basalts in the New England region.

Australian Journal of Mineralogy Volume 4 Number 1

Cover Photograph: Wulfenite, Whim Creek, Western Australia, 5mm long crystal, Photo: Ted Madden

The Mineralogy of the Oxidised Zones of the E22 & E27 Orebodies at Northparkes, New South Wales
M Crane, J Sharpe and P Williams

The E22 and E27 deposits at Northparkes have well-developed oxidised zones overlying thin secondary enriched zones. The main secondary minerals present are malachite, azurite, chrysocolla, libethenite and pseudomalachite. The distribution of these minerals is zoned, with copper phosphates occurring in the upper sections and copper carbonates dominating at depth. Chrysocolla commonly forms overgrowths on libethenite and azurite, which may later dissolve to leave chrysocolla endomorphs. The presence of visible gold in the lower oxide and supergene enriched zones suggests gold has been remobilised by the weathering of sulphides and enriched down profile. Native copper, cuprite, tenorite, chalcocite and digenite have been identified in the enriched zone.

End-Member Beyerite from the Alone Hand Mine, Cloncurry, Queensland
L Lawrence, A Ramsden, J Sharpe and P Williams

End-member beyerite, (Ca,Pb)Bi2(CO3)2O2 has been found at the Alone Hand mine, south of Cloncurry, Queensland. It occurs as an alteration product of bismuthinite in the oxidised zone of a gold-bearing orebody whose primary and secondary mineralogy is described. New data is given for beyerite from the Alone Hand, this being the first recorded Australian occurrence of the mineral and the first in which Ca is not partially replaced by Pb.

The Minerals of the Whim Creek Copper Mine, Western Australia
P Downes, J Bevan and A Bevan

For more than a century, the Whim Creek Mine has been the source of fine copper and lead minerals. In all, more than sixty minerals species have been recognised from the mine and includes the first recorded occurrence of murdochite in Australia.

Platinum Group Minerals from the Broken Hill District, New South Wales
S Elvy, N Gray, J McAndrew, P Williams and D French

Small deposits containing high platinum and palladium grades occur to the east of Broken Hill, New South Wales. Gossan samples have been examined from Mulga Springs, Little Darling Creek and Round Hill (Moorkaie Hill) to identify any platinum group minerals present. Platinum mineralogy is simple, being confined to braggite, sperrylite and native platinum, the latter being derived from oxidation of sperrylite. Palladium mineralogy is much more complex. Species found include Pd-Cu alloys, froodite, mertieite II, paolovite and several unnamed phases corresponding to (Cu,Pd)3Bi, Pd20(Te,Bi)3 and Pd3(Te,Hg)3. Copper-palladium oxides also occur, associated with goethite, malachite and chrysocolla. Secondary base metal mineralogy is also described. This is the first detailed report of the platinum group mineralogy of these deposits.

Australian Journal of Mineralogy Volume 3 Number 2

Cover Photograph: Diamond, Black Sands Creek, Beechworth, Victoria, 8.2 carats, Private Collection (collected 1975), Photo: Frank Coffa

The Coolgardie pegmatite field, Western Australia
M Jacobson

This notable Australian pegmatite locality has produced a range of lithium minerals as well as excellent specimens of columbite-tantalite group minerals.

The Daydream Mine, Silverton
J Leach

The Daydream mine now operates as a tourist mine but in its heyday was a rich source of silver. It is one of the few Australian localities where boleite has been found.

Iron phosphate minerals associated with ironstones in the Olary region, South Australia
P Ashley, B Lottermoser and K Scott

Ironstones occurring in the Proterozoic Willyama Supergroup in the Olary Block, South Australia, have been found to contain several uncommon iron phosphate minerals, apparently formed under supergene oxidation conditions. The minerals are fine-grained and occur as encrustations and cavity and fracture fillings, commonly in association with jarosite-type minerals. Two dark green phosphates, natrodufrenite and rockbridgeite, are the most abundant, but in places there are small amounts of strengite and chalcosiderite. The phosphate minerals may result from reaction between apatite in the ironstones or wedgetail eagle guano and Fe-bearing acid sulphate waters formed by oxidation of pyrite.

Saddlebackite, Pb2Bi2Te2S3, a new mineral species from the Boddington gold deposit, Western Australia
R Clarke

Saddlebackite, with an ideal formula of Pb2Bi2Te2S3 is a new mineral found in a gold-quartz specimen from beneath the lateritic gold orebody at Boddington, approximately 100km south-east of Perth, in Western Australia. It occurs in millimetre-sized aggregates in massive white quartz, intimately intergrown with gold, aleskite, tsumoite, altaite, galena and other, incompletely characterised, phases.

Australian Journal of Mineralogy Volume 3 Number 1

A Broken Hill Special Issue

Cover Photograph: Raspite with tabular stolzite, Broken Hill, Raspite crystal 4 mm long, Specimen: Museum of Victoria M33253, Photo: Frank Coffa

The Hall Collection - A Broken Hill treasure trove
A Pring

An article on the T Hall collection acquired by the South Australian Museum in 1909.

The Broken Hill mineral collection of Milton Lavers
B Day

One of the most significant collections of Broken Hill minerals remaining in Broken Hill belongs to Milton Lavers. The collection is housed in glass wall-cabinets lining three rooms, and consists of approximately two thousand specimens, varying in size from thumbnails to large museum sized specimens, all of superb quality for the species from Broken Hill. The specimens are carefully labelled and catalogued, and displayed with attention to their aesthetic quality.

Minerals of the Kintore and Block 14 open cuts at Broken Hill, NSW
B Birch and A van der Heyden

The Broken Hill silver-lead-zinc deposit, in far western New South Wales, has been a mainstay of the Australian mining industry for nearly 114 years. During this time it has also become renowned throughout the world as a source of rare, exotic and aesthetic mineral specimens. Such is its diversity, with nearly 300 recorded species, the deposit has been recognised as one of the world's 'mineralogical rainforests'.

Notes on other secondary mineral discoveries from the Broken Hill oxidised zone
B Birch and A van der Heyden

While most attention has been focused on minerals discovered in the Kintore and Block 14 open cuts, there have been interesting minerals documented from other parts of the oxidised zone over the past decade.

Minerals of the slags from Broken Hill, NSW
P Elliott

The slag resulting from smelting operations at Broken Hill, much of which is still lying where originally dumped, has also been subject to secondary alteration but the resulting minerals appear to have received little attention from mineralogists or mineral collectors.

Australian Journal of Mineralogy Volume 2 Number 2

Cover Photograph: Cuprite, Spring Creek, South Australia, Crystal 3.5 mm across, Specimen: South Australian Museum G1598, Photo: Brian Beyer

Portlandite and other recent mineral discoveries in the granites at Lake Boga, Wycheproof and Pyramid Hill, Victoria
W Birch

The granite outcrops at Lake Boga, Wycheproof and Pyramid Hill in northwestern Victoria have yielded many interesting minerals, including several new phosphate species. Further collecting has unearthed the rare calcium hydroxide portlandite, a silver iodide mineral and several more rare phosphates, including meurigite (a new species), zwieselite, and a so-far-unidentified CaCuBi-bearing compound.

Sector-zoning in Epidote from Jamieson River, Victoria: evidence for a replacement mechanism?
T Kwak and M Hendrickx

Research has been conducted on the sector-zoning of epidote from Cambrian greenstones in the Jamieson River region of east-central Victoria, Australia. The epidote is suggested to have formed during early prehnite-pumpellyite facies metamorphism but was partly to completely homogenised by internal re-equiliberation of the epidotes during latter greenschist facies metamorphism.

Minerals from the Spring Creek mine, near Wilmington, South Australia
B Beyer and P Elliot

The Spring Creek mine has long earned a reputation amongst Australian mineral collectors as a source of splendid miniature and micromount specimens of a variety of copper minerals, including the rare minerals hentschelite and perloffite.

Heulandite from the Illawarra District, NSW
P Carr, M Perkins, B Chenhall, J Pemberton and R Middleton

Attractive specimens of heulandite and prehnite occur in the basaltic Dapto Latite Member of the Illawarra District. The heulandite forms as colourless, glassy, well-formed tabular crystals with a maximum dimension of approximately 5mm and prehnite occurs as pale green rounded masses up to 1cm thick and 15cm across, formed by the radial alignment of platy crystals.

Australian Journal of Mineralogy Volume 2 Number 1

Cover Photograph: Winner of AJM Photographic Competition, Mimetite, Sabine's Shaft, Mount Bonnie mine, Near Pine Creek, Northern Territory, Specimen 2x5 cm, Photo and specimen: Brian England


Some Mines of the Mt Isa District, Queensland, Part 3 - The Mount Oxide Mine
B Day and B Beyer

The historic and remote Mt Oxide mine has recently been the source of a range of beautiful and rare minerals. It is the type locality for sieleckiite, and the phosphate and sulphate suites, in particular, are quite notable. This paper describes several species not previously recorded from the mine.

Zeolites and associated minerals from Borambil, NSW
B England

Tertiary basalt exposed in a road cutting near Borambil, New South Wales during roadworks in the early 1970s contained abundant vesicles lined with chabazite and thomsonite associated with calcite and an unknown silicate mineral occurring as flexible colourless hair-like crystals. Also present were rare levyne-offretite, analcime and phillipsite. These species are consistent with a silica-poor environment. Chemical compositions of the zeolite species as determined by energy dispersive X-ray microanalysis are uniform and fall within the composition ranges quoted in the literature. Microanalyses of the unknown silicate indicate a 3D framework structure [O/(Si+Al)=2] but its composition and morphology match none of the known framework-structured minerals. The locality is notable in that it is one of the few in New South Wales that contains abundant thomsonite.

The Francis Collection
A Pring

The mineral collection of Glyn and Maxine Francis is one of the best private collections ever assembled in Australia. Within it, the suite of 400 specimens from Iron Monarch in the Middleback Ranges of South Australia is probably the best and most complete collection from a single important Australian deposit.

Post-mine Sulphates from the Teutonic Bore base metal deposit, Western Australia
L Lawrence, P Clarke, C Stocksief and P Williams

The Teutonic Bore silver-lead-zinc-copper deposit lies some 60km north-west of Leonora in the North-east Goldfields of the Yilgarn Craton of Western Australia, 900km by road north-east of Perth. Since mining ceased in 1984, dump material has been oxidising at a substantial rate with soluble sulphates being carried into small depressions or swales adjacent to the dumps and there crystallizing during the long periods of hot dry weather. Similar salts are forming on the dumps themselves and it is quite likely that some of them, at least, also formed in the upper parts of the zone of oxidation, prior to the commencement of mining. All the minerals described here are post-mine products. The attractive range of bright blues, greens and white exhibited by the minerals at Teutonic Bore caught the attention of local geologists and much specimen collecting ensued.

Australian Journal of Mineralogy Volume 1 Number 2

Cover Photograph: Topaz, Strathbogie Ranges, Victoria, Crystal 1.2 cm high, Photo: Frank Coffa


Chalcophanite from Mount Stewart, NSW
B England

The Mount Stewart mine has long been famous for the specimens of pyromorphite and pyrite recovered during active mining around the turn of the century, and the mine dumps have continued to provide interesting specimens for the collector to the present day. Recently, well-formed crystals of chalcophanite have been found associated with fibrous coronadite lining cavities in a limonitic gossan outcrop adjacent to the Engine Shaft. The crystals are simple in chemical composition, showing none of the magnesium, nickel or lead substitution which is typical of many of the other localities for this species. They also provide exceptional micromounts.

Zeolites from Daylesford, Victoria
D Henry

A new Victorian zeolite locality has produced some attractive micromounts of chabazite and unusual aggregates of phillipsite.

Some Mines of the Mt Isa District, Queensland, Part 2 - The Mt Cobalt Mine
B Day and B Beyer

The Mt Cobalt mine has long been a source of large and spectacular specimens of erythrite. Close examination of specimens recently collected from old workings and mine dumps has revealed a range of colourful and unusual cobalt and copper-bearing species.