What is the Difference Between Similar But Different Things, Terms, and Objects

What is the Difference between Sapphire, Jade, Emerald and Ruby

Gemstone is a piece of mineral, which is used in jewelry after cutting and polishing. Different gem stones have different value, which depends on the cutting, polish and shine. Different myths are associated with different gems. Sapphire, Jade, Emerald and ruby are different gem stone and it is really difficult for a common person to understand the difference between them.