They matured only after thousands of years, and the glow they produced was caused by their inner light. Despite their biologic nature, rainbow gems could be used as lightsaber crystals. Tenel Ka Djo, the Princess of Hapes, had a tiara of rainbow gems worth the price of an entire solar system. She used some of the crystals in her second lightsaber, after her first one malfunctioned and led to the loss of her arm.
The gems, often used in medallions, were considered very valuable, as just one was worth the price of a Calamarian cruiser. Due to their great value and untraceable nature, these gems comprised part of a Huttese bribe to Admiral Winstel Greelanx to purchase the battle plans for his impending assault on Nar Shaddaa. The Huttese bribe of gemstones was delivered by the young Han Solo.
- Star Wars: The Old Republic: Rise of the Hutt Cartel
- The Hutt Gambit
- Star Wars Galaxies: An Empire Divided
- The Courtship of Princess Leia (First appearance)
- Young Jedi Knights: Shadow Academy (Mentioned only)
- Young Jedi Knights: Lightsabers
- Young Jedi Knights: Darkest Knight (Mentioned only)
- Young Jedi Knights: Jedi Bounty (Mentioned only)
- Young Jedi Knights: Crisis at Crystal Reef (Mentioned only)
- The New Jedi Order: Agents of Chaos II: Jedi Eclipse
- The New Jedi Order: Dark Journey
- The Apprentice"—Star Wars Gamer 8 "