Description Interesting Christmas Calendar: 24 types of rocks, gems, minerals and specimens with 24 openings, with different surprises every day, forming a lasting attraction for children. The Ultimate Specimen Collection: A perfect collection or add to any childs specimen collection, including 24 rough and polished ore samples. Be a great gift for boys and girls. Time Concepts: Geology is more exciting than breaking rocks and finding crystal treasures; calendars are also a great way to teach children numbers, time concepts, and the art of patience. Closed Packaging: It is difficult to find the internal products from the outside, which increases the childreninterest, so that children can find out small surprises every day. Parents can also add special surprises to their children on the designated date. Perfect Gift: Both children and adults like this gift. Specification: Material: Mineral, Paper Size: Approx. 21x16.4cm/8.27x6.46inch Package Includes: 1 Piece Christmas Advent Calendar (contains 24 ore specimens) Note: Please allow 1-3mm measuring deviation due to manual measurement. Due to the different monitor and light effect,the actual color of the item might be slightly different from the color showed on the pictures.!