Swargaloka gems are called mani , syamantaka mani is one of the four swargloka gems . It is known by various names in following in sanskrit neela showrirathna , indraneela , trunagrahi , neelamani , makooth , kabooth , saifar .
1. Syamantaka mani stone is blue in color .
2. It is worn by lord indra .
3. The story of syamantaka appears in the vishnu purana and the bhagavata.
4. The jewel originally belonged to the sun god, who wore it around his neck .
5. It was said that whichever land possessed this jewel would never encounter any calamities such as droughts, floods, earthquakes or famines, and would always be full of prosperity and plenitude.