Ratnapura gem gravels (illam)

Where: Sabaragamuwa · Asia · approx. 6.68, 80.4 (vicinity only)

Why this spot: Quaternary alluvial gem gravel over Precambrian highland complex

What turns up: Blue sapphire, star sapphire, ruby, spinel, garnet, moonstone, cat's-eye chrysoberyl, zircon in illam gravels

Access: Permission required.

Gemming is licensed under the National Gem and Jewellery Authority; pit mining is artisanal but requires permits, visitors buy from dealers

Satellite view, historic-map overlays, tide/flow context and field notes are in the app. Exact research detail is part of Pro.