Government agencies that issue participation certificates are Government National Mortgage Association, Federal National Mortgage Association, and Federal Home Loan Mortgage Corporation. These agencies issue certificates representing pools of mortgages, and investors receive monthly payments of interest and principal, like a mortgage lender would receive. You can invest in gold or other precious metals by purchasing bullion, coins, commodity futures, or gold mining stocks whose earnings are tied to the markets for those commodities. An advantage of investing in collectibles is that it may provide much enjoyment for some people. Some items, such as artwork, Chinese ceramics, or Oriental rugs, may be appreciated for their beauty.
Disadvantages are that the market value for many collectibles is usually completely unpredictable.
You need to be very cautious about deception, fraud, misrepresentation, or price gouging by unscrupulous dealers.