Feldspar was an ore found in asteroids. In 2083, an asteroid containing feldspar hit Terra Nova colony. Thermal shock caused by the impact of the asteroid on the planetary surface led to a toxic ore rain similar to nuclear fallout. (ENT: "Terra Nova") The real life mineral Feldspar is a form of crystalline silicate. Feldspar is believed to be the most common mineral on Earth, comprising approximately 60% of the planet's crust. Asteroids are known to commonly contain silicates. Also, breathing silicate dust is generally not a good thing.