Researchers say famous diamonds, including the Hope and Koh-i-noor diamonds, may have originated from a volcanic outcrop nearly 300km from where they were mined.
Researchers may have found the true origin of the Hope diamond, Koh-i-noor and other famous gems.
These diamonds, collectively known as Golconda diamonds, are special because they have few impurities and very little nitrogen, making them very clear and sparkling. These diamonds are quite large in size. The Koh-i-noor, now one of the crown jewels of Great Britain, weighs 105.60 carats. The Hope Diamond, on display at the Smithsonian National Museum of Natural History in Washington, DC, USA, weighs 45.52 carats.
These diamonds were discovered in southern India between the years 1600 and 1800.
Appeared after a volcanic eruption?
The Koh-i-Noor diamond is a large, transparent diamond. (Photo: World History Archive / Alamy Warehouse Photo)
Diamonds that appear on the Earth’s surface after large volcanic eruptions are called kimberlites.
The latest research just published in the Journal of Earth System Sciences suggests that the diamonds may have come from the Wajrakarur kimberlite mine in present-day Andhra Pradesh, up to 300 km from where they were mined.
To try to trace the origin of the Golconda diamonds, Hero Kalra, Ashish Dongre and Swapnil Vyas – all geologists at Savitribai Phule Pune University in India – studied the chemical signatures of kimberlites .
They discovered that kimberlite from the Wajrakarur mine likely emerged from the depths where diamonds are formed and contained minerals that tend to appear with diamonds.
They then conducted surveys using remote sensing data such as satellite images, vegetation and humidity measurements. These surveys suggest that an ancient dry river may have swept diamonds from Wajrakarur to the Krishna river and its tributaries.
