Studying rocks and minerals encourages a love for nature, enhances observational skills, and introduces key concepts in earth science. To use the Types of Rocks Sorting, identify and classify rocks from the three major rock groups: igneous, sedimentary, and metamorphic. Then, verify the classifications using the control charts. The following 18 rocks are included: andesite, basalt, gabbro, granite, obsidian, rhyolite, breccia, conglomerate, limestone, rock salt, sandstone, shale, gneiss, hornf