Back to The Strata Memo

Methodology and sources

What this site is

The Strata Memo tracks U.S. federal policy, funding and spending on the 60 minerals on the USGS 2025 List of Critical Minerals, next to basic facts about each mineral. It is a free, source-linked pilot. It is rebuilt from saved data, not live: each page says when the data was last checked.

Where the items come from

• Federal Register documents (rules, proposed rules and notices) from the Departments of Energy, Commerce, Treasury and the U.S. Trade Representative.
• Grants.gov funding opportunities, with deadlines and award ceilings as posted.
• Department of Energy news releases.
• USAspending.gov federal contracts and grants from the last 12 months, found by searching for each mineral name. These are awards already made, not calls for applications. Their date is the award start date, which can be in the future, and the amount is the money obligated so far, not necessarily the final total.

We link to the original for every item and record the date we last saw it there.

What counts as relevant

An item is marked relevant when its main subject, or a concrete action in it, concerns the supply, production, processing, recycling, stockpiling, trade or funding of critical minerals or materials. Items that mention minerals only in passing, such as one line in a list of priorities or the name of an agency office, are not marked relevant. Items where critical minerals are one named, funded target among several are marked "related": they are hidden by default and appear when you choose "Show related items".

Who decides

Each item is first scored by a keyword list, then read against the rule above by an AI model, which gives a label and a confidence. The AI must also copy a short quote from the original that shows the link to critical minerals, and our software checks that the quote really appears in the item's text. No quote that checks out, no tag. Items the AI is unsure about, or where minerals are only one target among several, are listed under "related". The tags on this site are generated by AI: a person does not review every item, so please use the link to the original to check anything that matters to you. If a person does review an item, its tag changes to "Reviewed by a person" and their decision replaces the AI tag. Award texts are in capital letters at the source; we show them in lower case, with sentence capitals added, for readability. Award headlines are the first sentence of the award description, shortened.

Mineral fact sheets

• Supply figures (U.S. net import reliance, world production and reserves, import sources, prices) come from the USGS Mineral Commodity Summaries 2026 data release (public domain). Values are printed as USGS gives them. Uranium and metallurgical coal have no USGS chapter, so their sheets have no supply figures.
• Trade: tariff rates are from the U.S. International Trade Commission Harmonized Tariff Schedule for a curated list of codes per mineral; imports and exports by country are from the U.S. Census Bureau International Trade API (calendar 2025 and the latest months of 2026). A code can cover goods beyond the mineral itself. Section 232 and 301 tariffs, emergency tariffs and anti-dumping and countervailing duties are not in the schedule and are not shown.
• Fun facts are written in our own words from a Wikipedia article and are shown only when a second, independent source also supports them. Where the two disagree, the contested detail is left out.

How often it updates

Data is refreshed about weekly and the pages are rebuilt then; between rebuilds the site does not change. Check the "data last checked" date on each page.

Limits you should know about

AI tags can be wrong, especially when an item only has a title. Awards are found by keyword in the award text and recipient name, so some are only loosely about critical minerals, and only the largest awards for each search term were collected, so the award list is not complete. Eligibility rules for funding are set by the original notice and are not summarized here, so read the source before you apply. Treasury and IRS guidance, SAM.gov contract notices, Defense Production Act and stockpile actions, export controls by other countries, and several agency news feeds are not yet included. This site is not legal or investment advice.

Source register and how to cite

Fact-sheet panels show a short source line. Full citations for each source are here; the retrieval date in the copied text is the date this page was built. To cite this site as the compiler, give the page title, its address and the date you retrieved it, and name the underlying source too.