Average size is between 1.9" to 3.9" per premium quality geode! Each and every specimen is unique and you will receive stones similar to the image shown! Manufacturered by rockcloud. To crack your geodefirst place it inside an old sock.Lay sock on concrete floor or sidewalkand tap geode with hammer. Great for educationchildrens partiesany rock enthusiast and home decoration! You will receive 1 PC Unopened and Uncracked Quartz Geode;WeightApprox):0.66-1.1 lb