https://smartasset.com/taxes/avoid-capital-gains-tax-on-gold

I don't think commodity trade is going to fly in USA

Consider a 1031 exchange

A 1031 exchange could offer you more flexibility, allowing you to defer the tax bill on a capital gains so long as you reinvest those profits in another investment asset.

Generally, you have to make this new investment within 45 days of selling the old one. It has to be a similarly situated investment, so if you sell gold you would need to reinvest the profits in precious metals. And you need to have an intermediary hold the money, because as soon as the capital gains hit your bank account they become taxable.