Answer to Map #90

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Answer: This week’s map was a proportional symbol map depicting the world’s most productive diamond mines. Thanks to David P. for creating this map for us to use!

Diamonds are created by extreme temperature and pressure deep in the earth’s mantle. They are only accessible in places where igneous rock from the mantle has been forced up closer to the surface. Only a few places have the right kind of conditions for diamonds to be accessible. As a result, a huge percentage of the world’s diamonds come from a tiny number of countries.

Before the nineteenth century, India was the only place where diamonds were readily accessible. Some of the world’s most celebrated diamonds had their origin in India. These included the Hope Diamond, which was mined in India in the 1660s and which is now on display at the Smithsonian in Washington, DC, and the Koh-i-Noor, which is now part of the British Crown Jewels at the Tower of London.

In the nineteenth century, commercial diamond mining took off in southern Africa, where British imperialists such as Cecil Rhodes established large mines. The biggest mine was at Kimberley in what is now South Africa. Rhodes was the driving force behind De Beers, the company that continues to dominate the diamond trade.

More recently, people have discovered diamonds in a wider variety of places, including in Canada and Russia. Canada had essentially no diamond mining industry at all until 1991, when two geologists found evidence of the rock that contains diamonds in the Northwest Territories. By 2006, these new mines were so productive that Canada had become one of the world’s five largest producers of diamonds.

Today, the biggest producer of diamonds is Russia, followed by Botswana. Botswana’s Jwaneng mine is the richest diamond mine in the world. Russia, however, is the country believed to have the largest untapped reserves of diamonds, and it seems likely that Russia will continue to dominate the diamond trade going forward. Then again, maybe not? It’s hard to predict where diamonds might be found next. And one of the most interesting recent developments has been the creation of an offshore mine in Namibia to mine diamonds from the floor of the ocean. Undersea mining is an important (and controversial!) new trend in the mining of all sorts of minerals, not just diamonds.

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