Spinel has long been found in the gemstone-bearing gravel.
Spinel has been a precious gem since ancient times. Because it’s beautiful and rare, it is also one of the world’s most glamorous gem. While spinel is sometimes treated as a poor imitation of ruby, individual stones can be quite valuable and may fetch high prices at the market if they are pure and have a strong, good color. Its melting point is 2135 degrees and the refractoriness is about 1900 degrees.