for geologist enthusiasts. Read the clues and select from several types of rocks trying to match the clues that are given. If you are correct. you'll know immediately. If you are incorrect, the game will give you the correct answer. There is a pointing finger that shows where you are in the game. After ten rocks, the game ends, but since there are samples of fifteen rocks, just play again. Great game if you don't have a hands-on rock collection.