Recent Note · 2026-06-14
On edge reflections in black volcanic glass
The most interesting part of this small obsidian fragment is not the dark body, but the thin grey reflection along one broken edge. Under indirect light, the surface appears almost flat; when tilted, several curved fracture lines become visible near the margin.
Locality
Unlabeled reference piece, kept for surface observation only.
Texture
Glassy luster with minor irregular marks and one clean conchoidal edge.
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Compare with a lighter basalt sample under the same desk lamp.