Delerium

Delerium is a magical mineral left behind by the meteor. It appears in geode clusters of translucent, sharp-edged crystals which reflect octarine light. The eldritch stones softly hum in dissonant tones, and glow brightly at night or when exposed to magic. Deposits are found throughout Drakkenheim, often fused into stone streets and buildings like crystalline moss.
A typical delerium fragment is about the size of a finger. Crystals may be fist-sized or slightly larger, and geodes may be as big as a pumpkin. Massive clusters might grow taller than a human.