Black Diamond is a quick solitaire game played with a traditional deck of cards. Place cards from the black suits (clubs, spades) to a diamond-shaped grid around four diamond cards, following these placement rules: suits must alternate, and the values must equal the sum, difference, product, or quotient or any number of touching diamond cards. Be careful, though - whenever a card limit has been reached or there are no legal moves, precious new diamond cards must be added to the grid. If you run out of the diamonds, it's game over, but if you manage to place all black cards to the diamond, you win!

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