4Investigate Gems introduces readers to what gems are and how they form, including mineral gems and organic gems. Learn about crystal systems, imitation and synthetic gems, cultured pearls, how gems are used, and their historic importance. A geology-themed project provides the opportunity for hands-on experience. Other features include a table of contents, fun facts, infographics, sidebars, map, and an index. Aligned to Common Core Standards and correlated to state standards. Checkerboard Library is an imprint of Abdo Publishing, a division of ABDO.