Features:1. This Advent calendar is made of high-quality, safe materials, suitable for children over 3 years old.2. The toy advent calendar is a fun way to allow children to count down every day until Christmas, and get surprises every day. This can cultivate their patience.3. This toy can keep your child away from electronic products and reduce stress. You can also practice numbers and counting skills with your child A rock collection is prepared for the children to surprise your little geologist, which will stimulate your childrens curiosity and love for science and geology.4. The countdown to Christmas is an exciting time for everyone. Using a countdown calendar is a way to increase holiday expectations.5. This is a great Christmas gift for children over 3 years old. A great scientific gift for mineralogy and geology lovers. Notice:1.Actual color may be slightly different from the image due to different monitor and light effect2.Please allow 1-3cm deviation due to manual measurementMaterial: Natural crystal stoneStone size: about 4~8mmincludes:1 box x Advent Calendar Mineral Rock