San Marcos opal area

Where: Jalisco · North America · approx. 20.78, -104.18 (vicinity only)

Why this spot: Fire opal in rhyolite on the western edge of the Magdalena opal belt, dug in small pits since the 1950s

What turns up: fire opal, hyalite, rhyolite matrix opal

Access: Permission required.

Small private and ejido claims, buy access or material from the diggers.

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