Black Volcano Agate Freeforms - Small 1-2" - UV Reactive Green

Black Volcano Agate is a trade name for a variety of UV-reactive chalcedony, a cryptocrystalline form of silica (SiO₂) in the quartz group. It forms in gas cavities within cooling lava, where silica-rich groundwater deposits fine banded layers over time, producing agate's characteristic microcrystalline structure.

In daylight the stone presents as deep black and grey with earthy, mottled banding, but under longwave UV light most pieces fluoresce a vivid green - a reaction attributed to trace uranium or other mineral activators trapped within the silica matrix during formation.

These freeform pieces have been polished to smooth, rounded surfaces that showcase the contrast between the stone's dark daylight coloring and its hidden UV glow. Size range: 1-2".

Origin: Madagascar | Crystal System: Trigonal (cryptocrystalline quartz) | Hardness: 6.5 - 7 | Composition: SiO₂

Metaphysically, Volcano Agate is associated with grounding and transformation - valued as a root chakra stone believed to support courage and breaking through old patterns.