Where: Borsod · Europe · approx. 48.12, 21.4 (vicinity only)
Why this spot: Miocene volcanics
What turns up: Common and precious opal, chalcedony, hydroquartzite in rhyolite
Access: Gray area.
Volcanic region; field collecting, some protected.
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.