Samarian spinel

The Samarian Spinel is a 500 carat spinel gemstone that is the largest of its kind in the world. It is part of the Iranian Crown Jewels.

Origins
It and a smaller 270 carat spinel were captured by the Persian King Nadir Shah during his 18th-century conquest of India.

The Samarian spinel has a hole in it. According to a diary entry of the court physician to the Iranian Shah Nasser al-Din Shah Qajar, the King told the physician that the stone once adorned the neck of the biblical golden calf, which the Israelites are said to have made while Moses was receiving the Ten Commandments. A diamond was added later to conceal the hole.