What makes a metal product IRA-eligible?
The tax code sets minimum fineness standards: gold at .995, silver at .999, platinum and palladium at .9995, produced by a recognized mint or accredited refiner. Products meeting those standards can be held inside a self-directed IRA; products that don't, can't.
The well-known exception is the American Gold Eagle, which is 22-karat (.9167 fine) but explicitly permitted by statute. The exception exists because Congress wrote it in, not because a dealer says so.
Why does eligibility matter before you buy?
Metal that doesn't meet the standard can't go into your IRA, full stop. If a transaction puts non-qualifying product into the account, you risk the IRS treating it as a distribution, taxes and potential penalties included.
This is why the custodian confirms eligibility before executing a purchase, and why 'collectible' coins, however beautiful or profitable, generally have no place in a retirement account.
How does eligibility show up in practice?
Before any IRA purchase, ask your custodian to confirm the specific product qualifies, in writing. A dealer's badge on a product page is marketing; the custodian's confirmation is what governs the account.