Black & Dark Crystals

What Makes Minerals Black & Dark?

Black in minerals results from several mechanisms. In obsidian, the dark color comes from concentrated iron and magnesium in volcanic glass. In tourmaline (schorl), high iron content absorbs virtually all visible light. In hematite, dense iron oxide packing creates opacity. In jet and shungite, carbon is responsible. Metallic black minerals like galena and magnetite appear dark because their metallic bonding absorbs and re-emits light at all wavelengths equally.