Diamond mining

Diamonds

Diamond and other gem mining companies

Of all the diamonds mined in the world each year, less than half are gem quality; the rest fall into two other main categories known as near-gem quality and industrial quality diamonds. Gem quality diamonds display a high standard of excellence in quality and are used in jewellery. The clarity of these diamonds ranges from flawless through to visible inclusions. Near-gem quality diamonds represent those stones of a quality between gem and industrial, that in fact can be used as either depending on the individual stone. These stones have clarity grades ranging from visible inclusions through to industrial. Industrial quality diamonds are low quality or badly included stones and are suitable only for industrial use; for example, they are used in dentist's drills and earthmoving equipment.

Diamonds are recovered by way of pipe or alluvial mining. Pipe mining refers to the extraction of diamonds from volcanic pipes. Typically, a very large area has to be covered. An average of 250 tonnes of ore must be mined in order to produce a one-carat gem quality polished diamond.
Alluvial Mining involves the extraction of diamonds from riverbeds or ocean beaches. Millions of years ago, at the time the diamond pipes were formed, some diamonds were weathered out of the pipes and carried great distances along rivers and even into oceans. In order to extract these diamonds from beaches, a wall is built to hold back the surf. Up to 25 metres of sand is bulldozed aside to reach the diamond-bearing level. Once reached, the diamond-bearing earth is removed and transported to screening plants.

Australian Diamond industry

As well as being Australia's only major diamond producer, the Argyle diamond mine is also one of the most technologically advanced mines in the world. The Argyle Diamond Mine is the world's biggest producer of natural diamonds and contributes approximately one-third of the world's natural supply. Australian Argyle Diamonds are internationally reowned for their unique brilliance and stunning array of colours. Unearthed in the rugged Kimberley region in the far north of Western Australia, Argyle Diamonds thrill in shades of pink, champagne, cognac and dazzling white.
Since its beginning, annual production has steadily increased from 29 million carats in 1986, to 40.9 million carats in 1993. The average annual production since 1994 has been over 35 million carats.