Chrysoberyl is the third-hardest frequently encountered natural gemstone and lies at 8.5 on the Mohs scale of mineral hardness. Chrysoberyl is yellowish-green and transparent to translucent.
The three main varieties of chrysoberyl are: ordinary yellow-to-green chrysoberyl, cat's eye, and alexandrite the most famous of all due to it change of color and its considered one the rarest of all gemstone and the most expensive if it has 100% color change. Main source of chrysoberyl is Sri Lanka, Madagascar, Tanzania, USA, Brazil, India and many more