Man Made Material (Simulated Mineral)

Sandstone

Arenite (primarily SiO2)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Tumbled goldstone-like quartz pebble

Likely iron-stained quartz or jasper; exact identification requires testing

Jasper

Silicon dioxide (Quartz variety), SiO2

Weathered fossiliferous limestone

Bioclastic limestone, chiefly calcite (CaCO₃)

Sandstone (with Iron Staining)

Arenite

Cubic Zirconia (Diamond Simulant)

Zirconium Dioxide (ZrO2)

Limonite

FeO(OH)·nH2O (Hydrated iron oxide)

Quartz

Silicon Dioxide (SiO2)

Leopard jasper (orbicular jasper)

Silicified volcanic rock, chiefly microcrystalline quartz/chalcedony (SiO₂) with feldspar and iron-oxide inclusions

Black Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Agatized Fossil (Druzy Agate)

Silicon Dioxide (SiO2) replacing organic matter

Obsidian

Volcanic Glass (70-75% SiO2 with MgO and Fe3O4)

Chert (Flint)

Chert (Silicon Dioxide, SiO2)

Limonite (Iron-rich Siltstone / Sandstone base)

Hydrous ferric oxide mixture (FeO(OH)·nH2O)

Fluorite on Host Rock

Calcium Fluoride (CaF2)

Granitic gneiss (weathered, rounded cobble)

Foliated granitoid; primarily quartz, feldspar, and mica (composition commonly approximates granite)

Weathered river stones, likely basaltic andesite and related volcanic rocks

Fine-grained mafic/intermediate volcanic rocks; commonly basalt (plagioclase + pyroxene ± olivine) or andesite (plagioclase + pyroxene ± amphibole)

Chert (Flint Nodules)

Chert (Silicon Dioxide, SiO2)

Sandstone

Arenite (primarily SiO2)

Sandstone (likely River-tumbled Picture Sandstone)

Arenite (predominantly SiO2 with iron oxide impurities)

Sand

Siliciclastic sediment / Quartz sand (SiO2)

Sandstone

Sandstone (Sedimentary rock composed of silicate grains)

Basalt with Quartz/Feldspar Inclusions

Amygdaloidal or Porphyritic Mafic Volcanic Rock with Siliceous Veining

Sandstone (with Iron Staining)

Clastic sedimentary rock (SiO2 with Fe2O3 oxides)

Sandstone

Arenite

Quartz-bearing iron-stained breccia

Brecciated quartz/quartzite with iron oxides, chiefly SiO₂ with hematite/goethite and possible feldspar or host-rock fragments

Dark mafic igneous rock, likely basalt or gabbro

Basalt–gabbroic rock; chiefly plagioclase feldspar and pyroxene, possibly olivine

Sandstone (likely Quartzose)

Arenite (SiO2 principal mineral)

Olivine in Basalt matrix

Peridotite (Mg, Fe)2SiO4

Quartz

Quartz (Silicon Dioxide, SiO2)

Quartz (Milky or Clear variety)

Silicon Dioxide (SiO2)

Fossilized Bone

Permineralized Vertebrate Bone

Quartz-rich feldspathic pebble, possibly granite or granitic gneiss

Quartz–feldspar aggregate, likely granite; dark inclusion may be biotite, hornblende, or iron-oxide staining

Sandstone (Ferruginous)

Arenite (Fe2O3 staining)

Likely weathered iron-rich stone

Uncertain; possibly limonite/goethite-bearing rock

Petrified Wood

Silicified Wood (SiO2)

White seed-bead gemstone strand, likely freshwater pearl or shell pearl

Pearl: nacreous calcium carbonate, chiefly aragonite (CaCO₃) in conchiolin; identification uncertain from image

Basalt (Vesicular)

Extrusive mafic igneous rock; primarily (Mg, Fe)2SiO4 (Olivine), CaAl2Si2O8 (Plagioclase Feldspar), and Pyroxene

Sandstone (Ferruginous)

Arenite with Iron Oxide cement

Turquoise

Hydrated phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O

Bumblebee Jasper

Calcite-bearing Volcanic Tuff containing Sulfur and Arsenic (Orpiment/Realgar)