Features: brand new and high quality Discover the crystal treasure: Break these rocks to reveal the amazing crystals inside! Geology is nothing more exciting than opening rocks and finding crystal treasures. A great exploration activity and a great gift for girls and boys! Colorful and diverse: Geodes can form a variety of crystals inside. These geodesic lines are hand-selected to bring you the best varieties. 100% natural geometry: These real specimens may be as large as a tennis ball or as small as a ping-pong ball. Children will love the pleasure of opening them to see the natural beauty inside. This exploration activity emphasizes fun and discovery! Study Guide: In a detailed full-color study guide, you will learn all the fascinating science behind the formation of geodetic instruments. National -Geographic educational toys make science and learning fun and are the perfect exploration gift for boys and girls! Satisfaction guaranteed: National- Geographic Discovery Series provides children with high-quality educational toys, full of fun! If your experience is not extraordinary, please let us know so that we can provide you with the right experience. Package Includes: 1 Set Explore Gem Toys Specifications: Material: Gypsum + Ore Package Size: Approx.9.8x9.8x13.6cm/3.85x3.85x5.35inch note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.