Gem Symbols

Stars

 * Many Crystal Gem outfits.

Triangles

 * On the floor of the Pyramid Temple.
 * Lapis Lazuli's dress.
 * On the floor of the Gem Warship.

Lozenges

 * On Pearl's flight suit. (pink)
 * On Peridot and Jasper's outfits. (yellow)
 * In the Ancient Sky Arena