Sunstones are the power-source of Dinotopia. They provide protection to the island by amending a high-pitched sound when placed in a sunstone holder that keep the Carnivores inside the Rainy Basin and the Pteranodons in the lower half of Canyon City. All towns and cities own a sunstone for protection in the miniseries and tv series.
A sunstone is usually shaped as an oval and usually smooth to the touch. It always glows bright white, due to the sunlight it takes in, then releases its stored energy slowly like a rechargeable battery. It comes in many sizes, ranging from one that fits in the palm of your hand to around the size of a bowling ball.