Diamond Mining in Australia

_{Argile Diamond Mine in Australia}

Australia is home to one of the most prolific diamond mines in the world. As one of the top four diamond producing nations, the country’s success was built on a strong mining tradition, that goes back to the start of the commercial expansion of the global trade across the world. Today Australia is one of the top natural resource producers in the world, with a strong presence in coal, iron, ore and other commodities. The wide-open spaces of the vast nation, with diverse geography providing the right environment for the mining of rare minerals, including diamonds. Australia over the years had built up a reputation for its supply of special coloured (fancy) diamonds, that come from the legendary Argyle mines from the East Kimberley region. Whilst much of the attention has been cornered by the famous fancy coloured diamond mining source, Australia pedigree in the diamond history is greater, and here we will engage some of the key aspects of this trade in the land down under.

Start of the Diamond Trade in Australia

The first diamond finding in Australia was recorded in New South Wales around 1851 around the time the gold rush in that particular region was underway. This is interesting, as this puts the date of diamond mining discovery even ahead of South Africa, the country and the part of Africa it was part of that set off the diamond trade globally. In terms of diamond discoveries, significant quantities were mined from alluvial deposits from the Copeton and Bingara in northeastern New South Wales. The famous eureka diamond (Australia’s first such gemstone) was discovered in 1867, which in its uncut state came in at over 21 carats. The largest diamond to ever come out of the country weighed over 104 carats, sourced from the Merlin diamond mines located in the Northern Territory. Given the extent of the nation’s landmass, other diamond findings were discovered in Australia in the time since. The advances in sediment sampling and technical improvements in new exploration techniques meant that by that during the later part of the 20th century, notably from the 1970s onward new diamond deposits were found. The most notable being diamond sources found in Ellendale, in the Eastern part of Western Australia in 1976, and the famous Argyle deposit found in 1979, in the northern part of the same state. Getting an overview of the history of these two mines is a good way to understand the diamond mining history of Australia.

Australia’s Mystery Mines: Argyle Diamond Mines

A key moment in the diamond mining history in Australia was the discovery of the Argyle diamond mines in 1979. Which built itself a reputation for being a source of large-sized diamond mines, and later as one of the world’s top sources for diamonds, most notably the famous Argyle pink diamonds. Until very recently Argyle was the top diamond mining Australia, accounting for about 90 per cent of Australia’s diamond production, and was the fourth biggest diamond-producing mine in the world by volume, producing millions of carats of diamonds per year, hitting a peak of 42 million carats in 1994. When it came to the production of fancy coloured diamonds, the mines produced varieties from white, blue, violet, to the rare and famous Argyle pink diamonds.

The story behind the emergence of Argyle diamond mines, from its start in the late 1970s, and its steady rise to prominence is an interesting one, as it followed the development in mining and surveying techniques that were making steady progress during its time. Things started with the discovery of volcanic pipe deposits in 1979. As the discovery of alluvial diamonds in the West Kimberley region, found along the Lennard River, in Western Australia for the source of these diamonds was initiated by a consortium of mining companies known as the Kalumburu Joint Venture, which later became the Ashton Joint Venture that would in 1979 discover the kimberlite pipes in the region. Interestingly the origins of the discovery have been traced to the efforts of a woman named Maureen Muggeridge, who is credited with discovering diamond samples in the floodplain that flowed in Lake Argyle; who later managed to trace them to their source: the Argyle (AK1) pipe. Once the diamond source was correctly identified work was underway to make it operational. This involved an arduous process of study and evaluation of the location, with the support of many stakeholders, the economic viability of the mines was determined, and work began in 1985 to mine the vast diamond reserves.

Argyle Diamond Mines and the Advance of Mining Technology

The process leading up to the start of mining operations in Argyle diamond mines are interesting to note. The evaluation programme of the mineral character of the location, which involved bulk sampling of the lamproite (sub-volcanic rocks that are formed via the cooling and solidification of magma) that carried the diamond mineral. Following the study, the appropriate mechanical methods for extracting the diamonds from their host (rock) was established. The first stage in the mining of Argyle diamonds was the alluvial mining operations: a process that involves separating the diamonds from sediment, that have washed away from their original location to a water source downstream. Such diamond sources, though often small in contrast to other types. Once the diamond-rich sediments are located near ocean shore or river beds; these potentials are removed, moved to dedicated processing plants where they are screened for diamonds. When it comes to offshore operations, which are larger in scale; specially constructed ships are used to pull out the diamond-bearing sediment from the ocean floor, and then the process for screening begins.

From Open-Pit to the Start of Underground Mining

Alluvial mining of the Argyle went on for a couple of years, but things ended in 1985, and so began the next stage in the mining process in Australia. Open-pit mining, the process that is naturally associated with diamond mining. Open-pit mining is a vast process, unlike the mining for sapphires and non-carbon based gemstones, is a major process involving major digging using heavy machinery, the blasting of waste rock, with the hole then being drilled to pave the way for the mining of the gemstones. A complex process that took advantage of the advances in mining technologies such as hydraulic excavators, large haul trucks, wheel loaders, bulldozers. Which made the vast and complex process feasible. The next key step in the process was the processing of the ore, which used dedicated plants to break down, screen the materials; including X-ray machines. Argyle mines peak operation hit in 1994 when the open-pit mining process was still going well. Plans were underway in 2001 for the next stage in the mining process. In 2003 work was underway for the establishment of an underground mining project, that took off in 2009. In 2013 Argyle’s underground mining operations began one that would continue to the end of the mine’s diamond production in 2020.

Into the late 2010s with the underground mining operations underway, involved greater financial investment. One such development is the block caving method, which involved auto mining technology, which was a first in such an industry. Block caving is a mining technique that requires a high level of initial capital to create an artificial cave, letting the roof progressively fall under gravity. Around this period, Rio Tinto was affected by the growing uncertainty of making additions, such a new block cave on an ore-body that was getting deeper and narrower. In the same year, the company started giving indications that the Argyle mine was nearing the end of its exploration period.

Argyle Pink Diamonds

No discussion of Argyle diamonds, and of Australia diamonds and its diamond mining industry, in general, is complete without an overview of the famous Argyle pink diamonds. The pink coloured (fancy) diamonds sourced from the Argyle mines are developed a worldwide reputation. The pink diamonds from these mines are unique in their character in that the origins of their colour remain a mystery to this day. Owing to their rarity the gemstones have been subject to great scrutiny over the years. The Argyle pink diamonds also includes a certain red variant that is mined from the same source. The uniqueness of these characteristics have made these pink diamonds into a distinct coloured gemstone category, that commands a unique demand around the world in special auctions; since they are now basically off the market.

Ellendale: Australia's Next Argyle Diamond Mine?

Argyle is not the only diamond minie in Australia. Far from it. Another rising star is the Ellendale diamond mine, also located in Western Australia. And has emerged as one of the world’s leading sources the extremely rare yellow (fancy) diamonds. With the major diamond pits E4 and E9 being the major source of diamonds, with their mining having started in the 2000s. The Ellendale E9 pit in 2002 and at the E4 pit in 2006. Mining at the E4 pit was suspended and the area mine has had a curious history, with a number of stops and starts, and even entered government administration in 2015. More recently the Australian government has expressed interest in this potential diamond source, and has committed itself to the task or restarting diamond production in the mines.