Where: Mexico · North America · approx. 20.9, -103.97 (vicinity only)
Why this spot: Rockhounding locality: fire opal in Tertiary rhyolite
What turns up: fire opal, precious opal, opal in rhyolite matrix
Access: Permission required.
Opal comes from working private/ejido mines; access and buying require arrangement with mine owners.
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.