Argyle diamond mine facts for kids
The open pit of the Argyle diamond mine. A large mining truck is visible on the road for scale.
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| Location | |
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 Argyle Diamond Mine
Location in Australia
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| Location | Lake Argyle |
| State | Western Australia |
| Country | Australia |
| Coordinates | 16°42′44″S 128°23′51″E / 16.71222°S 128.39750°E |
| Production | |
| Products | Diamonds |
| History | |
| Opened | 1985 |
| Closed | 2020 |
| Owner | |
| Company | Rio Tinto Group |
| Website | www.argylediamonds.com.au |
The Argyle Diamond Mine was a famous place in the remote north of Western Australia where diamonds were found. For a while, it was the biggest diamond mine in the world, producing millions of diamonds each year! But most of these diamonds weren't the super shiny ones you see in jewelry.
What made Argyle special was that it was almost the only place in the world where rare pink and red diamonds were found. It also produced other unique colors like champagne, cognac, and even some rare blue diamonds.
The mine closed down in November 2020, after working for 37 years. During that time, it produced over 865 million carats of rough diamonds. The company that owned the mine, Rio Tinto, has been working to clean up the site since then.
The Argyle mine was also special because it was the first successful diamond mine to dig for diamonds in a type of volcanic rock called lamproite. Most other diamond mines find diamonds in a different kind of rock called kimberlite.
Contents
About the Mine
The Argyle mine site covered an area about the size of 50 football fields. It stretched for about 1,600 meters long and between 150 to 600 meters wide.
How Diamonds Were Mined
At first, the Argyle mine used an "open-pit" method. This means they dug a giant hole in the ground, which eventually reached about 600 meters deep. The open pit closed in 2010. After that, they started digging for diamonds underground using a method called "block cave mining" from 2013.
Where the Mine Was Located
The Argyle diamond mine was in the Kimberley region, which is in the far northeast of Western Australia. It was located southwest of Lake Argyle, about 550 kilometers southwest of Darwin.
Because the mine was so far from any towns (about 185 kilometers from the nearest town, Kununurra), a special living camp was built right at the mine site. Most of the 520 workers traveled all the way from Perth, which is over 2,000 kilometers away! They would work for two weeks at the mine and then go home for two weeks. The mine also encouraged local people, including many Indigenous Australians, to work there.
History of Argyle Diamonds
People in Australia knew about small amounts of diamonds since the late 1800s. But they didn't know where these diamonds were coming from. In 1969, more diamonds were found in the West Kimberley area. This led to a big search across Western Australia to find the main source.
In 1979, a person named Maureen Muggeridge found diamond samples in a small creek that flowed into Lake Argyle. She soon followed the creek upstream and found the source of the diamonds. On October 2, 1979, the Argyle diamond pipe was discovered!
For the next three years, experts studied the area to see if it would be worth mining. In 1983, they decided to start mining. They began digging for diamonds in the creek beds right away. The big open-pit mine took 18 months to build and cost about A$450 million. The mine officially opened in December 1985.
What Made Argyle Diamonds Special
The Argyle mine was the fourth-largest diamond mine in the world by how many diamonds it produced. On average, it produced about 8 million carats of diamonds each year. Production was highest in 1994, when it produced 42 million carats! The open pit alone produced over 750 million carats of rough diamonds.
Most of the good quality diamonds from Argyle were brown. These diamonds used to be hard to sell. But the company, Rio Tinto, worked for ten years to make them popular by calling them "champagne" and "cognac" colored diamonds.
However, the company never had trouble selling the pink, purple, and red diamonds. These colors are very rare and in high demand, so they sold for very high prices. The pink diamonds were carefully cut and polished by a special team in Perth and then sold to customers all over the world.
The mine had facilities on site to process the ore and sort the diamonds. Once the diamonds were cleaned, they were sent to Perth for more sorting and sale. Many of the smaller diamonds were sent to India to be cut. This was because it was cheaper to cut small diamonds there, and Argyle often produced smaller diamonds than other mines.
Diamond Characteristics
The diamonds from the Argyle mine were generally not as high quality as diamonds from other mines. Only about 5% of the diamonds found were considered "gem quality" (good enough for jewelry), while the worldwide average is 20%.
Most Argyle diamonds (80%) were brown. About 16% were yellow, 2% white, 2% grey, and less than 1% were pink and green. Even though pink and red diamonds were a tiny part of the production, the Argyle mine was the only reliable source in the world, producing 90 to 95% of all pink and red diamonds!
Annual Diamond Tender
Every year from 1984 to 2021, a very special collection of the best pink diamonds was offered for sale. This was an exclusive, invitation-only event called the Argyle Pink Diamond Tender. For every million carats of rough pink diamonds the mine produced, only about one carat of polished pink diamonds was offered at this special sale.
In March 2009, Argyle also held its first tender for rare blue diamonds. This collection, called "Once in a Blue Moon," included beautiful blue and violet diamonds that had been collected over several years.
In 2016, the pink diamond tender had its highest sales ever. The 2020 tender, which was the second-to-last one before the mine closed, set even more records. The very last tender in 2021 also had record-breaking results.
Mine Closure
The Argyle mine stopped producing diamonds on November 3, 2020. This decision was made because it was no longer profitable to dig for diamonds there. The remaining diamond ore was processed for about six more months. After that, the company began a ten-year project to restore the land, working with the traditional owners of the area. Sales of the last diamonds from the mine continued into 2022.
See also
- Argyle Pink Jubilee
- Argyle Airport
- Argyle Library Egg
