You're thinking of the bank account deposit reporting threshold.
"Gold and silver jewelry, like bullion, is also considered a collectible. So if you sell your bullion jewelry for a profit, it is subject to the same maximum 28% capital gains rate for precious metals and must be reported on your income tax return. Current law does not require that dealers report jewelry sales, even when dealing with 22K or 24K bullion-grade pieces, or in quantities above the 25 ounce limits applied to bars and many coins."
If you pay a US person at least $600 in the year, you must report that to the IRS on a Form 1099, usually a 1099-MISC. You don't report individual transactions, you simply report all of the income paid to that person over the course of the tax year. (For foreign persons, the form is the 1042-S, and there is no minimum threshold.)
Like the comment I was replying to, you both are conflating the anti-laundering reporting rules with the IRS income tax reporting rules.