2020-21 Upper Deck Black Diamond Hockey. This is an authentic black diamond gemography auto diamond card of Wayne Gretzky. It's card number G-WG and serial numbered 7/10.It's in mint condition. I can not guarantee the final grade if sent out. The item "Wayne Gretzky 2020-21 Upper Deck Black Diamond Diamond Gem Auto/Autograph /10" is in sale since Sunday, April 25, 2021. This item is in the category "Sports Mem, Cards & Fan Shop\Sports Trading Cards\Trading Card Singles". The seller is "dr13at3rd" and is located in Warrington, Pennsylvania. This item can be shipped worldwide.