The Koh-i-Noor diamond

The Koh-i-Noor is one of the largest cut diamonds in the world, weighing 105.6 carats and part of the British Crown Jewels.

Probably mined in Golconda, India, there is no record of its original weight, but the earliest well-attested weight is 191 carats or 38.2 gr. Koh-i-Noor is Hindi and Persian for “Mountain of Light”. It has been known by this name since the 18th century. It changed hands between various factions in modern-day India, Pakistan, Iran, and Afghanistan, until being ceded to Queen Victoria after the British conquest of the Punjab in 1849.

Originally, the stone was of a similar cut to other Mughal era diamonds which are now in the Iranian Crown Jewels. In 1851, it went on display at the Great Exhibition in London, but the lacklustre cut failed to impress viewers. Prince Albert, husband of Queen Victoria, ordered it to be re-cut as an oval brilliant. By modern standards, the culet is unusually broad, giving the impression of a black hole when the stone is viewed head-on; it is nevertheless regarded by gemologists as “full of life”.

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 and Pakistan have both claimed rightful ownership of the Koh-i-Noor and demanded its return ever since the two countries 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.