How many Precious Gems are there in the world?

The exact number of precious gems in the world is difficult to determine, as it depends on how one defines "precious." Traditionally, the most recognized precious gems include diamonds, rubies, sapphires, and emeralds. However, there are many other gemstones classified as semi-precious, and new gemstones are continually being discovered. Overall, the number of different types of gemstones is in the hundreds, encompassing a wide variety of colors and qualities.