Sedimentary Like (Industrial Composite)

Banded Sandstone (Quartzite-rich)

Clastic Sedimentary Rock (SiO2 with Iron Oxide impurities)

Siltstone

Siltstone (composed of mixed silicate minerals and clay)

Banded Gneiss

Gneiss (pronounced 'nice')

Agate (Grey Agate Slice)

Microcrystalline Quartz (SiO2)

Chert / Jasper

Microcrystalline Quartz (SiO2)

Chert (often called Flint)

Chert (Microcrystalline Silicon Dioxide, SiO2)

Polymictic conglomerate (possibly impact breccia)

Lithified polymictic conglomerate/breccia; clasts appear mainly mafic volcanic rock, with quartz- or feldspar-rich fragments in a dark matrix

Copper Nugget

Native Copper (Cu)

Laterite

Laterite (Iron and aluminum-rich residual rock)

Fossil brachiopod or bivalve shell

Indeterminate fossilized shell; likely a ribbed brachiopod (Order Productida or Spiriferida)

Mica-rich Sandstone or Micaceous Schist Weathering

Micaceous Schist (Muscovite-Quartz composition)

Chert (Jasper/Common Opal transition)

Microcrystalline Quartz (SiO2) with iron oxide inclusions

Rounded weathered stone, likely quartz-rich sandstone or fine-grained volcanic rock

Indeterminate hand specimen; probable quartz–feldspar sandstone (SiO₂-rich)

Possible fossilized bone or tooth fragment

Indeterminate fossilized vertebrate material; mineralized hydroxyapatite replaced or coated by silica/carbonate

Quartz Crystal (Geode Fragment)

Silicon Dioxide (SiO2)

Leopard jasper (orbicular jasper)

Silicified volcanic tuff/chert; predominantly microcrystalline quartz (SiO₂) with iron oxides and volcanic minerals

Likely petrified wood or silicified fossil fragment

Silicified wood; predominantly microcrystalline quartz (SiO₂)

Chert (specifically Gray/Black Chert)

Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)

Orange Calcite

Calcium Carbonate (CaCO3)

Likely tumbled yellow calcite or aragonite

Calcite (CaCO₃) or aragonite (CaCO₃)

Flaked stone projectile point

Likely worked chert or fine-grained silicified shale; exact lithology cannot be confirmed from the image

Chalcedony (Agate/Quartz variety)

Cryptocrystalline Quartz (SiO2)

Chert (often called Flint or Jasper)

Silicon Dioxide (SiO2)

Satin Spar (Selenite)

Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O

Phyllite

Phyllite

Agate Geode

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Polished dark gemstone, likely hematite or magnetite

Hematite (Fe₂O₃) or magnetite (Fe₃O₄); exact identification requires testing

Sandstone with Secondary Mineral Encrustation

Arenite with Silica/Calcite deposits (SiO2 or CaCO3)

Polished brecciated jasper (likely ocean jasper or orbicular jasper)

Microcrystalline quartz/chalcedony (SiO₂) with iron-oxide and other mineral inclusions

Barite Rose on Marcasite

Barium Sulfate (BaSO4) on Iron Sulfide (FeS2)

Rough Garnet (Almandine)

Almandine Garnet (Fe3Al2(SiO4)3)

Golden Calcite

Calcium Carbonate (CaCO3)

Ruby (Raw Corundum)

Al2O3 (Aluminum Oxide)

Polished orbicular jasper

Orbicular jasper; microcrystalline quartz (SiO₂) with hematite/goethite and other silicate inclusions

Turquoise

Turquoise - CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)

Quartz pebble

Silicon dioxide (SiO2)

River Siltstone / Mudstone Pebble

Siltstone (composed of mixed silicate and carbonate minerals)

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Hematite

Iron Oxide (Fe2O3)

Agate

Agate (Silicon Dioxide - SiO2)

Fluorite

Fluorite (Calcium Fluoride, CaF2)

Milky Quartz (Crystal Cluster)

Silicon Dioxide (SiO2) - Quartz Variety