If the FMV of the property is equal to or greater than the donor's adjusted basis, your basis is the donor's adjusted basis at the time you received the gift. PUB 551
When you sell it, you will have a capital gains tax. Net capital gains from selling collectibles (such as coins or art) are taxed at a maximum 28% rate. Collectible
If you know about when it was purchased, you may be able to look at historical gold prices.
