Where: Yen Bai · Asia · approx. 22.1, 104.7 (vicinity only)
Why this spot: Marble-hosted metamorphic
What turns up: Ruby, pink sapphire, and red-lavender spinel in marble; also cobalt-blue spinel.
Access: Permission required.
Artisanal and licensed mining; gems bought at the Luc Yen market. Not open collecting.
Open in Mudlark Map →
Satellite view, historic-map overlays, tide/flow context and field notes are in the app. Exact research detail is part of Pro.
Pins are approximate by design. This page is historical research, not permission to dig. Check ownership and local law first.