Syamantaka, Syamantaka mani, or the Shyamantaka Jewel, is perhaps the most famous jewel in Hindu mythology, supposed to be blessed with magical powers.
Read more about Syamantaka: Origin, A Gift From The Sun God, Theft and Recovery, Krishna's Marriage To Satyabhama, Deaths of Satrajit and Satadhanwa, Legacy, Syamantaka Ruby or Shyamantaka Blue Sapphire?, See Also