Emerald is the most beautiful and precious kind of rock. They are bright in color, crystal texture, brilliant luster, hard and durable, and rare. They are natural mineral crystals that can be used to make jewelry, such as diamonds, crystals, emeralds, rubies, sapphires, and golden emeralds (Allex, cat’s eye) Etc.
there are also a few natural single mineral aggregates, such as agate and opal. There are also a few organic materials, such as amber, pearls, coral, coral, and ivory, which are also included in gems.