Man Made Byproduct (Often Mistaken For Obsidian Or Emerald)

Shale or Siltstone

Sedimentary Rock (Siliciclastic)

Orange Calcite (Banded Calcite)

Calcium Carbonate (CaCO3)

Quartzite

Quartzite (SiO2)

Quartzite River Rock

Quartzite (Silicon Dioxide, SiO2)

Banded Agate (Chert/Chaldcedony)

Silicon Dioxide (SiO₂)

Quartzite

Quartzite (primarily SiO2)

Quartz pebble

Silicon Dioxide (SiO2)

Schist

Mica Schist

Quartzite Pebble

Quartzite (SiO2)

Quartz (Crystal Point/Fragment)

Silicon Dioxide (SiO2)

Quartz Geode (with possible Manganese or Goethite coating)

Silicon Dioxide (SiO2)

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

Agate

Silicon Dioxide (SiO2)

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

Petrified Wood

Silicified Wood (primarily Silicon Dioxide, SiO2)

Quartzite

Quartzite (primarily SiO2)

Quartzite

Quartzite (primarily SiO2)

Sandstone

Arenite (Siliclastic sedimentary rock)

Quartz pebble

Silicon dioxide (SiO2)

Sandstone (Weathered)

Arenite (primarily SiO2)

Amygdaloidal Basalt

Amygdaloidal Basalt (with secondary mineral infilling)

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrous ferric oxide)

Quartzite Pebble

Meta-quartzite

Blue Apatite

Apatite (Group), Ca5(PO4)3(F,Cl,OH)

Limonite with Trace Fossils

Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)

Fluorite (often called Rainbow Fluorite or Purple-Green Fluorite)

Calcium Fluoride (CaF2)

Schist

Mica Schist (Quartz-Muscovite-Biotite Schist)

Olivine (Peridotite/Dunite)

Olivine (Mg,Fe)2SiO4 within Peridotite

Quartzite

Quartzite (SiO2)

Nephrite Jade

Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2), a variety of Actinolite-Tremolite

Raw Diamond

Diamond (pure Carbon, C)

Green Quartzite

Quartzite (SiO2)

Sandstone

Arenite (primarily SiO2)

Fossil Coral

Cnidaria fossil (often Calcium Carbonate / CaCO3)

Quartzite

Quartzite (primarily SiO2)

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Red Sandstone

Arenite (Fe2O3 rich)

Green Fluorite

Fluorite (Calcium Fluoride, CaF2)

Sandstone (Ferruginous)

Arenite (with Iron Oxides)

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily SiO2)

Serpentinite

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4

Shale

Mudstone/Shale