Stratum Study
What is this, where is it from, and may I keep it?
803 articles on fossils, formations, localities, geologic time, minerals and shells, with the collecting rules of the United States by state and of forty countries — every fact cited to the database or text it came from, free to read, built to load on any phone.
Taxa 193 ·Formations 43 ·Localities 33 ·Time intervals 181 ·Minerals 120 ·Shell families 40 ·Techniques 23 ·Law & ethics 37 ·How-tos 12 ·Glossary 121
Holding a certificate?
Verify it
Every certificate Stratum issues carries a QR to verify.stratum.black. The page checks the registry and re-verifies the signature in your browser, so the verdict does not depend on trusting us.
For dealers and collectors
Stratum for iPad and iPhone
Inventory with the science attached, provenance that travels with the piece, signed certificates a buyer can check years later, a table-day point of sale, and this reference offline. Dealers publish lots to the Exchange, where anyone can make an offer from a browser.
Pilot with dealers for Tucson 2027. Write to drew@tyr.ac.