Red Sandstone

Arenite (composed primarily of SiO2 with Fe2O3 cementation)

sedimentary

Sandstone (with Liesegang rings or joints)

Clastic Sedimentary Rock (primarily Quartz with Iron Oxide cement)

sedimentary

Lapis Lazuli (Tumbled Stone)

Na6Ca2(Al6Si6O24)(SO4,S,Cl)2 (Lazulite-rich Metamorphic Rock)

metamorphic

Labradorite

Labradorite ((Ca, Na)(Al, Si)4O8)

mineral

Geode (Unopened)

Siliceous Concretion / Geode

sedimentary

Granite

Phaneritic intrusive felsic igneous rock

igneous

Smoky Quartz and Feldspar Pegmatite

Granitic Pegmatite (chiefly SiO2 and KAlSi3O8)

igneous

Ferruginous Quartz

Silicon Dioxide (SiO2) with Limonite/Hematite inclusions

Mineral

Scoria (Vesicular Basalt)

Vesicular Basaltic Andesite

igneous

Chert (specifically Flint or Jasper variant)

Microcrystalline Quartz (SiO2)

sedimentary

Amber

Succinite (fossilized resin)

mineraloid

Carnelian (Chalcedony)

Silicon Dioxide (SiO2)

mineral

River Cobble (Basaltic/Andesitic)

Mafic Igneous Porphyritic Rock

igneous

River Stone (Basalt Porphyry)

Porphyritic Basalt

igneous

Jasper

Silicon dioxide (SiO2)

sedimentary

River Pebble (Quartz/Jasper)

Silicon Dioxide (SiO2)

sedimentary

Zoisite with Ruby (Anyolite)

Zoisite – Ca2Al3(SiO4)3(OH) with inclusions of Ruby (Al2O3:Cr)

metamorphic

Agate (specifically Botswana or Lake Superior style Agate)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

mineral

Chert (Nodule)

Microcrystalline quartz (SiO2)

sedimentary

Carnelian (Orange Agate/Chalcedony)

Silicon Dioxide (SiO2) - variety of Chalcedony

mineral

Amethyst

Amethyst (Silicon Dioxide - SiO2 with iron impurities)

mineral

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

mineral

Green Opal

Hydrated Silica (SiO2·nH2O)

mineraloid

Rose Quartz

Silicon Dioxide (SiO2)

mineral

Mixed collection of Quartz varieties, Chalcedony, and metamorphic pebbles

Mixed gemstones (primarily Silicon Dioxide - SiO2)

mineral

Chert (River Pebble)

Microcrystalline Quartz (SiO2)

sedimentary

Carnelian Agate

Chalcedony (Silicon Dioxide, SiO2)

mineral

Pink Quartzite

Quartzite (SiO2 with iron oxide impurities)

metamorphic

Basalt (Beach Pebble)

Extrusive mafic igneous rock

igneous

Chert (containing Calcite or Quartz inclusions)

Silicon Dioxide (SiO2) with varying mineral impurities

sedimentary

Sandstone (Ferruginous)

Arenite (primarily SiO2 with iron oxide cement)

sedimentary

Sandstone (likely Quartzose Sandstone)

Arenite (primarily SiO2)

sedimentary

Amber

Succinite

Mineraloid

Quartz Pebble

Quartz (Silicon Dioxide - SiO2)

mineral

Sandstone (with man-made markings)

Arenite (composed primarily of Quartz, SiO2)

sedimentary

Sandstone (Ferruginous)

Arenite (SiO2 with Fe2O3 inclusions)

sedimentary

Quartzite (River Stone)

Metamorphosed Quartz Sandstone (SiO2)

metamorphic

Quartzite Pebble (with Quartz veins)

Quartzite (SiO2)

metamorphic

Sandstone (Quartzose)

Arenite (primarily SiO2)

sedimentary

Gneiss (Granitic Gneiss)

Gneiss (composed primarily of Quartz, Feldspar, and Mica/Amphibole)

metamorphic

Jasper

Jasper (Silicon Dioxide, SiO2)

sedimentary

Orange Calcite

Calcium Carbonate (CaCO3)

mineral