Koroit

Koroit est située à 100 km nord - ouest de Cunnamulla, sur la route de Humeburn. L'opale a été découverte en 1902 et l'exploitation a démarré en 1903.

 

Le text suivant vient du livre de Len Cram:- BEAUTIFUL YOWAH - Black Gate & Koroit
Publié & Distribué par Len Cram
PO Box 2
Lightning Ridge
NSW 2834
www.opalcutter.com.au
Phone: (02)6829 0527
ISBN 0 64626007 3 1995

En anglais.
The field was first worked by a private Glasgow syndicate known as the "Scottish Australian Opal Company".

They originally prospected the area with drills, shafts and tunnels. For their day it was quite scientific. They were looking not only for the beds of nuts and boulders; but the channels and faults in the band at the junction of the sandstone and opal dirt where pipe and free opal formed.

There was on average ten men employed, who by the end of 1904 had completed 150 shafts between 5 and 15 metres, as well as six water shafts with the capacity of 80,000 litres.

From these shafts 472 metres of drives were completed, and 300oz of medium grade and 30oz of fine grade opal was produced.

The selected amount of boulder matrix was one and a quarter ton.

A considerable amount of propecting was carried out within an eight kilometre radius of the workings, mainly by drilling.

The estimated amount of opal and matrix produced was 2000 pounds. This was at a time when London market was under pressure from an influx of low grade opal, especially from White Cliffs. Because of the depressed prices the company decided to reserve their parcels of opal and closed down operations for a period of time, leaving only a caretaker on the field.

For reasons known only to the syndicate the mines never went into production, even though their chief engineer had designed a successful underground pueumatic digging machine.

By 1906 the field lay dormant. Like the Yowah, Koroit has had a checkered history, but it wasn't until after World War 2 that any strong interest was again taken in the field.

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