Feature: The countdown to Christmas is an exciting time for children. Using a countdown calendar is a way to increase holiday expectations. Advent Calendar is a great Christmas gift, and every day has a new surprise This Advent Calendar is made of high quality, safe and nontoxic materials, and is suitable for adults and children over 3 years old. Include rough and polished samples of rock. Make wonderful gifts for girls and boys This toy can keep your children away from electronic products and relieve stress. You can also practice numbers and counting skills with your children Provide children with rock collection kits, and surprise your little geologist, which will stimulate your children's curiosity and interest. This is an ideal Christmas gift for children over 3 years old. Great scientific gift for mineralogy and geology lovers. Discover the crystal treasure Each kit contains a broken crystal hole and two complete crystal hole specimens for you to open by yourself. Geology is nothing more exciting than opening rocks and searching for crystal treasures.