There are 5 different colored Gems: blue, white, green, black and red, totaling 4 of each color. In addition, there are two Pearls.
Gems and Pearls are used to buy Jewel cards from the pyramid. Gems can be found in Tokens, or in acquired Jewel cards as Bonuses. Pearls can only be found in Tokens, as there are no Pearl bonuses.
You can not have more than 10 Gem and Pearl tokens at the end of your turn. If you do, you need to discard down before the next players turn.