Anthropogenic (Man Made Material Mimicking Sedimentary Rock)

Sandstone Anvil / Nutting Stone

Quartzose Sandstone (Sedimentary Rock)

Note: This is a Man-Made Object (Costume/Prop Patch)

Synthetic fiber and pigments (Cellulose/Plastic-based composite)

Ironstone Concretion

Ironstone (primarily Siderite or Limonite)

Iron Slag

Iron/Steel Slag (Ferrosilicate Glass)

Dyed Agate / Painted Stone

Silicon Dioxide (SiO2) with artificial pigment

Dzi Bead (Etched Chalcedony)

Cryptocrystalline Quartz (SiO2) with chemical etching

Crackled Quartz (Dyed)

Silicon Dioxide (SiO2)

Chert Concretion

Chert (Microcrystalline Quartz, SiO2)

Chert Arrowhead

Microcrystalline Quartz (SiO2)

Polished black pebble, likely basalt

Basalt, a fine-grained mafic volcanic rock composed mainly of plagioclase feldspar and pyroxene, commonly with olivine

Metal Alloy (Likely Pewter or Sterling Silver)

Not a natural geological specimen; composed of refined metals. If pewter, it's a tin-based alloy. If sterling silver, it's 92.5% silver and 7.5% other metals (usually copper).

Conglomerate

Conglomerate Rock (Paraconglomerate)

Opalite

Synthetic Glass (Amorphized Silicon Dioxide)

Clay Brick

Ceramic structural unit (Al2O3·2SiO2·2H2O as precursor)

Sea Glass

Man-made vitreous material (silica-based glass)

Crushed Stone (Likely Limestone or Granite)

Calcium Carbonate (CaCO3) for Limestone / Quartz and Feldspar for Granite

Eroded Brick or Pumice-like Scoria

Vesicular Basalt / Scoria (Anthropogenic variant: Eroded Firebrick)

Ocean Jasper Mushroom

Orbicular Jasper (Silicon Dioxide, SiO2 mixed with various impurities)

Green Sea Glass

Amorphous Silica (man-made glass), SiO2 + additive metal oxides

Slag (Industrial Byproduct)

Anthropogenic Vitreous Silicate material

Gastropod Internal Mold (Steinkern)

Class Gastropoda fossil mold (Phylum Mollusca)

Rainbow Hematite Ring

Iron(III) oxide (Fe2O3) with thin-film coating

Titanium Coated Kyanite (Aura Kyanite)

Aluminosilicate (Al2SiO5) with a Titanium-Niobium vacuum-deposited coating

Opalite

Synthetic Glass (Hydrated Silica Simulant)

Blue Obsidian (Cullet Glass)

Silicon Dioxide (Amorphous Glass)

Red-orange jasper pebble (tentative)

Microcrystalline quartz, SiO₂, colored mainly by iron oxides

Mohave Turquoise (Composite/Stabilized)

Hydrated copper aluminium phosphate (CuAl6(PO4)4(OH)8·4H2O) with stabilizing resin and metallic inclusions

Blue Obsidian

Volcanic Glass (SiO2 with inclusions)

Opalite (Synthetic Moonstone/Sea Opal)

Silicon Dioxide (SiO2) glass with metallic inclusions

Clear Quartz Sphere (Rock Crystal)

Silicon Dioxide (SiO2)

Blue cabochon gemstone, likely synthetic glass or dyed stone

Indeterminate from image; possible glass, synthetic spinel, sodalite, or lapis lazuli

Polished obsidian

Volcanic glass; predominantly rhyolitic SiO₂

Quartz pebble (Quartztite fragment)

Silicon Dioxide (SiO2)

Sandstone Concretion

Clastic sedimentary rock (primarily Quartz SiO2)

Nutting Stone / Cupstone (Sandstone or Quartzite)

Sedimentary rock with anthropogenic modification (cupule)

Opalite

Man-made opalescent glass

River Pebble / Chert Pebble

Microcrystalline Quartz (SiO2)

Sandstone Concretion

Clastic Sedimentary Rock (primarily SiO2 with mineral cement)

Rounded graywacke or sandstone cobble

Lithified clastic sandstone; likely quartz–feldspar–lithic grain aggregate in a silica or calcite matrix

Chert Concretion (with typical hematite/limonite staining)

Sedimentary Concretion (SiO2 with FeO(OH)⋅nH2O)

Man-made Synthetic Material (Costume Faux Fur)

Synthetic Polymer (Polyester/Acrylic)

Painted River Rock

Anthropogenic-modified Siliciclastic Sedimentary Rock