Calcium was a substance which could be used as fuel in demolitions. The Mandalorian artist and demolitions expert Sabine Wren used calcium in as fuel in some of her explosives as it created orange explosions, which she used in her "art". She listed the substance and the color it produced along with other fuels which produced colored explosions in her journal about five years before the Battle of Yavin.
Calcium also comprised certain starship fuels during the Galactic Civil War. It was present on Jakku in the Graveyard of Ships as a hazard to scavengers on the planet's surface. It possessed an orange color in the sand, identifying it and warning those of its presence. Rey identified the substance in her journal about twenty-nine years after the Battle of Jakku.