What is a rock? And what's the difference between a rock, a mineral, and a gem? Kids are sure to discover the answer in this addition to our Smithsonian First Discovery Books! Every page of the board book is filled with interesting facts from the different layers of rocks which make up the earth, to the identification of precious and semi-precious gems. Do you know why the Hope Diamond's color is named French Blue? Learn the answer to that question and more in this fascinating book.Smithsonian Kids books feature engaging and educational content for little learners that reflect the integrity of the Smithsonian. A portion of the proceeds from the sale of this book goes to support the Smithsonian's educational mission.