4In a very deep cave in Mexico, massive crystals grow much larger than a human. Cave of Crystals looks at when and how these crystals formed and what the future looks like for these formations. Easy-to-read text, vivid images, and helpful back matter give readers a clear look at this subject. Features include a table of contents, infographics, a glossary, additional resources, and an index. Aligned to Common Core Standards and correlated to state standards. Kids Core is an imprint of Abdo Publishing, a division of ABDO.