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You can purchase gems in-game from the Black Lion Trading Company, but starting this week you can also purchase Guild Wars 2 gems in real life at select retailers. These cards, which make a great gift, contain a serial code that can be redeemed in Guild Wars 2 for gems.
If gem cards aren’t in stock at your favorite retailer yet, be sure to ask if and when they’ll be arriving.
For redemption instructions and additional information about gems, visit the Guild Wars 2 Support page.