- "They can slice through transparisteel like a laser goes through Sullustan jam."
- ―Lando Calrissian, on the strength of Corusca gems
Corusca gems, also called Corusca jewels or stones were extremely rare and valuable crystals. They were produced by a combination of the extreme pressures present in the atmosphere of Yavin Prime—pressures great enough to crush elements together—and the scraping of the liquefied air of the planet against its metallic core. The sizes of Corusca gems increased with proximity to the core of Yavin. They could be found only in very select locations in the galaxy, and their vibrancy resulted in them becoming the namesake of the galactic capital: Coruscant. The Corusca Gem casino was also named after these gems.
Corusca gems were mostly valued for their beauty. The way that light reflected inside a Corusca gem would make it seem as if it had a furnace within it. As a result, there were many Corusca gem fisherman, such as Bash Fateau, who made a living out of collecting the gems.
Corusca gems were some of the hardest objects known to the galaxy, and had industrial as well as decorative applications. Large Corusca gems were mounted on drills and used for precision drilling when explosives could not be used.
Despite their well-known strength, Corusca gems had shatterpoints, minuscule points where multiple edges and facets would come together, forming an extremely weak spot. If delivered at exactly the right point, and exactly the right way, the slightest tap could cause the entire gem to crumble.
Supreme Chancellor Palpatine once tempted Anakin Skywalker with a bag of Corusca gems as an example of how he could have anything he wanted, if only he were to ask for it. Skywalker, however, was not interested, as the only thing he truly wanted at the time was to prevent the death of his wife, Padmé Amidala, which he had seen prophesied in a Force vision.
Jacen Solo used a Corusca gem worth the price of an entire Coruscant city block, which he acquired at GemDiver Station, Lando Calrissian's mining station, to power his lightsaber. Ganner Rhysode was another Jedi known to use a Corusca gem in his lightsaber, until it was destroyed by Jacen Solo when he feigned alliance with the Yuuzhan Vong.
- Galaxy Guide 2: Yavin and Bespin (As "Corusca Stones") (First mentioned)
- Galaxy Guide 2: Yavin and Bespin, Second Edition (As "Corusca Stones")
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