Besides coins, since 1997 the IRS has allowed investors to use IRA funds to buy precious metals bullion such as silver or gold bars. Like coins, your bullion is stored for you, for a fee. Your custodian arranges it.
The following metals can be purchased with an IRA, subject to standards of purity: gold, silver, palladium and platinum.
Again, Green says she's not a fan, at least for IRAs. For one thing, once you reach age 70½, you're required to start taking required minimum distributions from a traditional IRA by April 1 of the following year. The distribution is a percentage of your IRA's value. If you're holding bullion "you'll have to get it valued every year" to compute your minimum distribution.
Another issue, in her opinion: "It doesn't perform over time. It's all peaks and valleys."