Print, follow the link to the pdf, then cut out the cards, turn them face down, mix them up, and turn them over to match all the pairs. While this is in color, a black & white printer works as well.

Mineral Memory copy

a1 b1 c1 d1 e1 f1 g1 h1 i1 j1 k1 l1 m1 n1 o1 p1 q1

a b c d e f g h i j k l m n o p q r s t