This Collection contains 20 Types of Basic Rocks Specimens of Igneous, Sedimentary & Metamorphic Rocks Types. The Rock Specimens include Basalt, Gabbro, Granite, Obsidian, Pegmatite, Pumice, Anthracite, Gneiss, Marble, Quartzite, Serpentine, Slate, Chalk Lumps, Conglomerate, Diatomite, Flint,...