You can trade your NFG on an open marketplace. The NFG's are always redeemable for the physical item no matter how many times they have changed hands. Alternatively, you can HODL your NFG and redeem or sell at a later point.
Claim your physical Gem by depositing your NFG on the Claim and Deposit page. NFG's will only redeem a specified Gem which is highlighted in the NFG's listing description. NFG's and Gems are given ID #'s. This allows prospective buyers and owners to match the art to the physical asset. ID #'s can be found on the NFG image and in the Gem product description. To view physical Gems and unclaimed Gems with additional photos visit the Gems page.