Samarian Spinel
The Samarian Spinel is part of the Iranian Crown Jewels and is the world's largest gemstone of its kind made from spinel .
The gem weighs 100 g and has 500 carats. The stone was stolen together with a smaller spinel (270 carat; 54 g) by the Persian conqueror Nadir Shah in the 18th century during a sack of India . On the smaller spinel there is a 350 year old inscription that refers to the former owner Jahangir , a Mughal ruler in India.