Washing and sorting through the stones

Some information on the gemfields, and a brief rundown on what a sapphire is, all gratefully sourced from www.fossicking.com.au:

The central Queensland gemfields centred on the small town of Anakie are known worldwide for their sapphire deposits. The gemfields comprise of the about 10 towns including the ones obviously named after the discovery such as Sapphire, Rubyvale and Emerald.

Little of the early history of the Anakie sapphire fields has been accurately recorded. The first discovery of sapphire near Retreat Creek was in the early 1870s but the first commercial production did not occur until the early 1880s. By 1903 sapphire mining, centred on two camps (now Rubyvale and Sapphire), was an established industry. The 1960s saw increasing prices and the beginning of machine mining, sparked by the appearance of buyers acting for interstate and overseas interests. They also saw the first conflicts between machine and hand miners. The appearance of buyers from Thailand who accepted large quantities of lower grade stones for heat treating led to a high level of activity and increasing mechanisation until 1977. Conflicts between various interests on the fields remained, there were difficulties in administration, and illegal mining was rife. Much of the area between Rubyvale and Sapphire was opened to machine mining at this time. After 1977 a downturn in demand began as other overseas deposits, in particular Sri Lanka, were opened to the Thai buyers. Their control of markets worldwide continued. The 1980s saw significant changes on the anakie gemfields. Production continued to fluctuate as prices for sapphire rose and fell as a result of new deposits and technologies world-wide. Many machine miners abandoned the anakie gemfields to mine other commodities such as tin and gold because of higher prices. In 1985, the potential of an active tourist industry, with sufficient gembearing ground to support it, was recognised. The Mining (Fossicking) Act 1985 was introduced and Designated Areas and Fossicking Areas were established in 1986. Up until 1988, Australia produced up to 70% by volume of the world’s sapphire, but this decreased to about 25 - 30%.

What is sapphire?
Sapphire is a variety of the mineral corundum. It consists of aluminium oxide (alumina) and has the chemical formula Al2O3. Pure alumina is colourless, but its occurrence is rare in nature because various metallic elements occurring as impurities in the crystal lattice impart colours to the mineral. Traditionally, the name sapphire was used for clear, blue, corundum stones. Nowadays, except for the red variety which is called ruby, it is common to refer to corundum of other colours also as gem stones (green sapphire etc). The blue stems from titanium and ferrous iron impurities, whereas the yellow and the green results from variable amounts of ferric iron and ferrous/ferric iron respectively. The red of ruby comes from chromium. Sapphire has a hardness of 9 on Mohs' scale, second only to diamond. Crystals are commonly rounded to barrel - shaped showing hexagonal bypyramid form. The value of sapphire as a gemstone stems from its hardness, range of colours and brilliant lustre.