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Sapphire from Australia

 

History of Australian Sapphires

Rough Australian SapphiresDuring the 1870’s, blue sapphires were first discovered in Queensland which augured a bright future for the international sapphire industry which at that time was already in frantic need of good quality natural sapphires. Although reports of first occurrence go back twenty years to New South Wales, when some sapphires were discovered during gold mining operations on the rivers Macquarie and Cudgegong, their commercial production began in the end of the 19th century. The early sapphires mined were exported to Europe. A number of sapphires found their way to Russia via the Russian miners who mined for sapphires in Queensland fields.


The Various Colors of Sapphires from Australia

Australian sapphires are primarily of blue, green, and yellow colours. Many parti-color (bi-color) and orange sapphires were also noted. Australia alone accounts for nearly more than half of the world’s sapphire production. Despite a larger production of blue sapphires, the most sought-after stones from Australia are the Yellow and Green Sapphires. The colours can be classified into five important groups viz. blue/blue-greenish, yellow/yellow greenish, bi-colored/parti-colored, bronzy/brownish reddish, and milky white/milky blue.


Sapphire Mining Locations

Thought some sapphires have recently been found in Tasmania, sapphire deposits are mainly concentrated in Queensland and New South Wales.

Sapphire Mining in Queensland – Sapphires are found in the areas surrounding the Anakie district. The area covers around 500 square kilometers. Sapphires are also found in Rubyvale, Willows-Glenlava and Tomahawk creek. Lava Plains area around Queensland produces some gem-quality blue sapphires. Around 200 kilometers north of Townsville, the area around Wyandotte creek also reports some sapphires.

Sapphire Mining in New South Wales – Blue sapphires are found in New England district. The sapphires are primarily concentrated around Inverell area. Other smaller but significant deposits have been found in Crookwell, Oberson/Porters Retreat, Gulgong, Vegetable Creek, Airly mountains, Bingara and other locations. However, despite these several locations, the sapphires from Inverell area remain the main competitors for the Thai-Origin (Pailin) sapphires.


Chemical Composition of Australian Sapphires

The sapphires from Australia are very rich in iron, which gives the blue sapphires their dark blue color. Iron is also responsible for giving the green color to the green sapphires. Color zoning is commonly seen. Dense clouds of rutile are also very often observed.


Sizes of Sapphires from Australia

Amazing Trilliant-Cut Australian SapphireSapphires of over three carat size are found in gravels along with garnet and zircon. It is reported that an astounding 217.5 carat yellow sapphire was found in Rubyvale around 350 km west of Rockhampton in 1946. It is a common misconception that Australia has no good quality sapphires, but the reality is that many exclusive museum-quality sapphires have originated in Australia but they have been sold as the more popularly known Ceylon/Burmese Sapphires.


Geological Origin

It is safe to say that most of the Australian sapphires are derived from Basalt flows. This also explains the very dark colours as they are very rich in iron. In the Queensland fields, sapphires have been found in the bank of creeks and are found in clayey or loose alluvium. The sapphires of New South Wales are also found as alluvial deposits of recent age. All these sapphires found in alluvial deposits are thought to be carried by rivers from their original basaltic source rock. Due to high density these have not travelled far from source.


Heat Treatment Prospects

Blue SapphiresAs with all sapphires, any new source found has been vigorously tested and experimented upon by heat treatment for improvement of clarity/colour by Thai treaters. The heat treatment of Australian sapphires had started much earlier before their commercial production in 1930’s in Idar Oberstein, Germany. By 1960’s heat treatment was prominent in Thailand. Of all sapphires those found at Lava Plains have been noted for dramatic improvement in overall appearance after heat treatment. The Australian sapphires are mainly heated to dissolve the rutile silk, reduce the green coloration and to lighten the existing inky dark blue.

 

 

Some Australian Sapphires from our Stock:

 



0.89-Carat Super Lustrous Unheated Australian Yellow Sapphire





4.89-Carat Extremely Rare Multi-Color Sapphire from Australia





2.38-Carat Dark Blue Australian Sapphire (Natural & Unheated)





1.00-Carat Rare Copper Brown Sapphire from Australia





4.93-Carat Extremely Rare Tri-Color Sapphire (Unheated)





2.11-Carat Unique Purplish Blue Australian Sapphire (Unheated)





4.64-Carat Marvellous Dark Green Sapphire from Australia




 

More Australian Sapphires

 

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