How is tiger’s eye different from cat’s eye? Is it bigger? Is it more wild looking? Well, tiger’s eye is yellow to brown colored and made of quartz and another mineral, while the best cat’s eye is green and made of chrysoberyl and another mineral. In tiger’s eye, the quartz has thin crystals of limonite (a kind of iron rust) in it that seem to move when you turn the stone back and forth. Both tiger’s eye and cat’s eye get their names from the way cats’ eyes have pupils that look like a line instead of the circular pupils that people have. A cat’s eye gem has a single line that looks like an eye that keeps looking at you as you turn the gem. A polished tiger’s eye gem may have one line or several lines, and as you turn the gem in different directions, the lines seem to stay in the same place. If you’re describing a gem that has a cat’s eye (or tiger’s eye) effect, you say it’s “chatoyant,” which would translate literally from the French as “cat-eye-like.”