Mineral Like Byproduct (Technogenic)

Satin Spar Selenite

Gypsum (Calcium Sulfate Dihydrate, CaSO4·2H2O)

Asphalt (Bituminous Rock)

Natural bitumen or Bituminous limestone/sandstone

Sandstone (Ferruginous)

Arenite (Fe2O3 staining)

Sandstone (likely Quartzose)

Arenite (SiO2 principal mineral)

Black Tourmaline

Schorl (NaFe2+3Al6(Si6O18)(BO3)3(OH,F,O)4)

Sandstone (Ferruginous)

Arenite with Iron Oxide cement

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Sandstone with Magnetite and Iron Staining

Clastic Sedimentary Rock (contains Fe3O4 and Limonite/Hematite)

Native Gold Nuggets

Native Gold (Au)

Sandstone

Arenite

Septarian Nodule (Dragon Stone)

Carbonate concretion (Calcite and Aragonite in Limestone/Clay)

Mahogany Obsidian

Volcanic Glass (with inclusions of Magnetite or Hematite)

Sandstone Pebbles

Arenite (primarily SiO2 with mineral cement)

Limonite with Quartz (Gossan)

Hydrated iron(III) oxide-hydroxide mixture (FeO(OH)·nH2O) with Silicon Dioxide (SiO2)

Fossil Shark Tooth

Carcharadon sp. (likely Carcharodon carcharias or similar Lamniformes)

Sandstone

Arenite (SiO2 secondary)

Septarian Nodule (Dragon Stone)

Septarian Concretion (CaCO3 with Siderite and Calcite)

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily SiO2)

Azurite and Malachite

Cu3(CO3)2(OH)2 (Azurite) / Cu2CO3(OH)2 (Malachite)

Banded Siltstone

Banded Siltstone / Laminated Siltstone

Gossan (Limonite/Ironstone)

Hydrated Iron Oxide (FeO(OH)·nH2O)

Geode

Quartz / Chalcedony nodule

Sandstone Pebble

Quartz Sandstone

Sandstone (likely Arkosic or Ferruginous)

Arenite (SiO2 with iron oxides or feldspar)

Granite Pebble

Intrusive Igneous Rock

Potassium Feldspar (Orthoclase / Microcline)

KAlSi3O8

Petrified Wood

Silicified wood (primarily SiO2)

Acrylic or Resin (Synthetic Imitation)

Polymethyl Methacrylate (PMMA) or Polyepoxide

Sandstone (Ferruginous)

Sandstone (primarily SiO2 with iron oxide Fe2O3 staining)

Petrified Wood

Silicified Wood (SiO2)

Sandstone

Arenite

Clear Quartz (Faceted)

Silicon dioxide (SiO2)

Sandstone (Greywacke)

Arenite/Greywacke (SiO2 major)

Obsidian Fetish Carving with Turquoise Inlay

Volcanic Glass with Turquoise (CuAl6(PO4)4(OH)8·4H2O)

Basalt (River Cobble)

Mafic Igneous Basalt (composed primarily of Plagioclase feldspar, Pyroxene, and Olivine)

Ammonite Fossil

Ammonoidea (subclass)

Satin Spar (often marketed as Selenite)

Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O

Sandstone (with vugs)

Arenite / Sedimentary Sandstone

Sandstone (Greywacke)

Arenite / Greywacke Sandstone

Raw Emerald in Matrix

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Clear Quartz

Silicon dioxide (SiO2)