'the light of the eye') is one of the largest pink diamonds in the world, and the centre piece of the tiara of the same name.

It was brought into the Iranian Imperial collection after Nader Shah of Iran looted Delhi in the 18th century.

[citation needed] The Noor-ul-Ain is believed to have once formed part of an even larger gem called the Great Table diamond.

The tiara forms part of the Iranian crown jewels, held at the National Treasury of Iran in the Central Bank in Tehran.

[citation needed] Anna Malecka, "The Mystery of the Nur al-Ayn Diamond", Gems & Jewellery: The Gemmological Association of Great Britain, volume 23 (7), August/September 2014, pp.