Fig. 01 — Stratum StudyEdition 2026.09

What is this, where is it from, and may I keep it?

1268 cited articles on fossils, formations, localities, geologic time, minerals and shells — and the collecting law of every US state and forty countries. Every fact carries the database or text it came from. Free, no account, loads on any phone in the field.

Index runs in your browser. Nothing you type leaves the page.

Fig. 02 — Drill
plate: drill card, Knightia eocaena

Learn to name it

Twenty cards a set, four choices a card, scored in the page. Fixed order, so a whole class sees the same deck. One URL to hand out; no account.

Open a set →
Fig. 03 — Time
181 intervals · ICS 2024

Put it in time

The full ICS column, walkable from eon to stage, with the formations and taxa that sit in each band and the ages they span.

Walk the column →
Fig. 04 — Law & ethics
plate: US map, collecting status by state

Know if you may keep it

Federal, state and private land in the US; export rules in forty countries. Each rule dated and cited, so you can show your work at a border.

Read the rules →
Fig. 05 — For dealers

The same record sells the piece and proves it.

Inventory with the science attached. Provenance that travels with the specimen. Certificates signed on the device and checkable by a buyer years later. A point of sale built for a show table, offline, with this whole reference in it.

Signed certificates
Secure Enclave key, QR to the public verifier
Table-day point of sale
Tap to Pay, pay-by-link, cash, negotiated prices
The Exchange
Publish a lot; buyers offer from a browser
Shopify · eBay · Etsy
One draft, every channel, disclosure written in
Holding a certificate?

The page checks the registry and re-verifies the signature in your own browser. The verdict does not depend on trusting us.

Stratum is the inventory, provenance and certificate system for fossil, mineral and shell collections. Study is its open reference: every fact cites its source, and the credits page lists each one with its licence.