What is syamanthakam?

Answer 1

It is a mythical jem in Hindu mythology, that Krishna gets from Jaambavaan.

In fact, the jewel was with Sathrajit, Sathyabhama's father. In a fight between Sathrajith's son who wore this jewel and went to forest and Gandharva/Rakshasa,

he lost both jewel and his life. As Lord Krishna once asked Sathrajit to have the jewel, which was refused, the blame of killing and stealing was put on Krishna and clearing the onus paved the way to meet Jambavan who had it from the Gandharva/rakshasa. In the ensuing fight between Jambavan and Krishna, the former was subdued and he in appreciation of the valour, gave the jewel and Jambavathi to Krishna. The jewel was restored to Sathrajit who in turn gave it to Krishna along with his daughter Sathyabhama.