Rocks

Pumice: igneous, extrusive, felsic, holes, very light

Tuff: igneous, extrusive, materials that were ejected by a volcano fell to earth and than lithified into a rock, volcanic ash and sometimes larger particles

Conglomerate: sedimentary, clastic sediments, large round particles, space is filled with small particles, chemical cement

Breccia: sedimentary, clastic sediments, large angular fragments, space is filled with small particles/chemical cement

Sandstone: sedimentary, clastic sediments, sand-size weathering debris, rough surface

Shale: sedimentary, clastic sediments, clay-size debbris, smells earthy

Marl: sedimentary, clastic sediment, fine grained, consisting of clay and calcium carbonate, reacts with acids, smells

Limestone: sedimentary, chemical sediment, calcium carbonate, reacts with acid, formed from precipitation of CaCO3 from lake or ocean water

Rock salt: sedimentary, chemical sediment, evaporation of saline water, dissolved material become oversaturated and precipitated, smells satly, greasy feel

Gypsum: sedimentary, chemical sediment, found in layered sedimentary deposits, in association with rock salt, white to gray or salmon coloured

Chert: sedimentary, chemical sediment, microcrystalline rock of SiO2 (silicon dioxide), breaks with a conchoidal fracture, very sharp edges

Radiolarite: sedimentary, organic sediment, siliceous, fine grained, composed of microscopic remains of radiolarians

Coal: sedimentary, organic sediments, formed from plant debris, low density

Gneiss: metamorphic, high grade metamorphism, same minerals as granite, shows layers/bands

Schist: metamorphic, fine, layers, mica -> shiny, intermediate metamorphism

Slate: metamorphic, folliated, very fine, shale or mudstone

Marble: metamorphic, non-folliated, compact mass, formed from crystals, reacts with acids, limestone or dolomite