An increase in production of $5.38 million from 1985 resulted from significant increase from Mintabie, moderate increase from Coober Pedy and a slight increase from Andamooka. Mintabie production which was $4 million more than Coober Pedy in 1986,...

Marked downturn in production and level of mining activity.

Exploration for Mississippi Valley type (MVT) lead zinc along the western margin of the Park has been confined to the upper part of the Wilkawillina Limestone of the Cambrian Hawker Group, where surface lead, zinc and copper mineralization and karstic...

Investigations have disclosed lead zinc mineralization as open - space filling, in the upper part of the Cambrian, Wilkawillina Limestone. Lead, zinc and copper mineralization is associated with dolomitization, facies changes, and karstic features...

For a project to determine the base metal potential of known copper-mineralised igneous rocks which outcrop in an area located approximately 59 km south-west of Olary, the South Australian Government has completed detailed mapping, geochemical...

Report criticises the methods, presentation and conclusions of a non-professional chrysoprase mining feasibility study prepared for the Commonwealth Government Opposition by parliamentary advisor J.P. West.

There is no abstract created for this record

Agate or banded chert nodules weather out of the Cambrian Andamooka Limestone over an area of several square kilometres south of the Stuart Creek Opal field. In places the agate nodules are concentrated into extensive deflation lag gravels. Banding is...

There is no abstract created for this record

Small quantities were mined from 1977 to 1978. The opal infills joints in leached and weathered Cretaceous shale. Considerable potential exists for further small finds of opal.

These diggings have produced precious opal within weathered Cretaceous Marree Subgroup, infilling fractures in claystone, capped by ?Miocene silcrete. At Sarda Bluff and Ouldburra Hill opal with colour also cements coarse sandstone, some of which may...

Discusses papers presented and gemstone industry in Sri Lanka.

Downturn in the industry is shown by the value of production from $34 210 000 in 1981 to $28 760 000 in 1982, and continuing decline in the numbers of registered claims and opal miners.

Production 1978 - 1985 has averaged $25 000 000 per year. Mining is now mainly by mechanized methods in underground workings, most of the older shallower fields having been worked out. All areas of deeply weathered Bulldog Shale, or Russo Beds...

The Dudley pegmatite, located 10.5 km south-east of Penneshaw, was worked during the 1890s and early 1900s for gem tourmaline, ceramic-grade feldspar and silica, and kaolin for brickmaking. The pegmatite outcrop strikes in a north-easterly direction...

Data was gathered from a literature review and from government authorities in 11 countries. Excluding China, world production of nephrite since 1962 has averaged 780 tonnes / year, dominated by Taiwan averaging 444 tonnes / year, but mining has ceased...

The bibliography includes nephrite jade, geology, gemmology and rare jade carving, but not jadeite. References include SADME unpublished reports. Includes computer printouts of GEOREF, GEOARCHIVE and NTIS.

Two specimens were probably formed by partial dissolution of Andamooka Limestone erratics within Cretaceous marine sandy clay, followed by replacement of the remaining carbonate rock by fine grained silica together with growth and deposition of silica...

At Andamooka during May - September 1976, 65 shafts were sunk and 399.5 metres of drives were developed. Payment to miners totalled $6018.30. The opal level was intersected in 54 shafts and was well developed in 39 of those shafts. Opal, mainly potch...

Decline in opal production of $1.56 million from 1983, but significant increases occurred at Andamooka and Mintabie, which is rapidly becoming a major mining centre approaching that of Coober Pedy, with an increasing trend for underground mining. At...