where do most of the worlds diamonds come from
Diamond Diamonds are far from evenly distributed over the Earth. A rule of thumb known as Clifford's rule states that they are almost always found in kimberlites on the oldest part of cratons, the stable cores of continents with typical ages of 2.5 billion years or more.[14][19]:314 However, there are exceptions. The Argyle diamond mine in Australia, the largest producer of diamonds by weight in the world, is located in a mobile belt, also known as an orogenic belt,[20] a weaker zone surrounding the central craton that has undergone compressional tectonics. Instead of kimberlite, the host rock is lamproite. Lamproites with diamonds that are not economically viable are also found in the United States, India and Australia.[14] In addition, diamonds in the Wawa belt of the Superior province in Canada and microdiamonds in the island arc of Japan are found in a type of rock called lamprophyre.[14]
Koh-i-Noor Today, the diamond is on public display in the Jewel House at the Tower of London, where it is seen by millions of visitors each year. The governments of India, Pakistan, Iran, and Afghanistan have all claimed rightful ownership of the Koh-i-Noor and demanded its return ever since India gained independence from the UK in 1947. The British government insists the gem was obtained legally under the terms of the Last Treaty of Lahore and has rejected the claims.