Anthropogenic (Man Made Material Mimicking Sedimentary Rock)

Pet Rock (Man-made Quartzite or Granite Cobble)

Silicon dioxide (SiO2) mixture; commonly composed of Quartz, Feldspar, and Mica

Chert (Chalky Flint Node)

Chert (Microcrystalline Quartz, SiO2)

Ferro-silicate Slag

Industrial Vitrified Slag (High-silica amorphous glass)

Concretion (Sandstone)

Carbonate-cemented Sandstone Concretion

Ring with an Orange Inlay

N/A (Man-made object)

Opalite

Synthetic glass / Opaque silicious glass

Asphalt (Bituminous Concrete)

Bituminous mix / Anthropogenic conglomerate

Metal Chain Belt with Square Plates

Not applicable (man-made)

Sandstone Concretion

Siliciclastic Concretion

Polymer Clay (Mock Mineral)

Polyvinyl chloride (PVC) with plasticizers and pigment

Blue Sea Glass

Amorphous Silica (Anthropogenic glass)

Sandstone (with man-made markings)

Arenite (composed primarily of Quartz, SiO2)

Beads (likely glass or man-made material)

N/A (artificial material)

Colorless quartz crystal (likely quartz fragment)

Quartz, silicon dioxide (SiO₂)

Red Sandstone or Brick Fragment

Arenite (if sandstone)

Opalite (likely man-made glass)

Opalite is a trade name for opalescent glass, not a natural mineral; composition is typically silica glass with additives

Chert (Arrowhead Shard)

Microcrystalline silica (SiO2)

Tumbled clear quartz (rock crystal)

Quartz, silicon dioxide (SiO₂)

Synthetic Faux Fur Fursuit

Polyacrylonitrile / Polyester (Synthetic Textile)

Faceted clear gemstone in a gold-colored setting

Unidentified transparent faceted stone; possibly quartz, glass, or another colorless gem

Crescent Pebble

Weathered Quartzite or Sandstone Fragment

Tumbled Clear Quartz/Rock Crystal

Silicon Dioxide (SiO2)

Tumbled milky quartz

Quartz (SiO₂), cryptocrystalline-to-massive variety

Blue opalite glass cabochon (likely imitation opal)

Man-made opalescent glass; not a natural mineral

Sea Glass (specifically Frosted White)

Amorphous Silica (substance: Sodium-calcium silicate glass)

Weathered iron-rich concretion or ironstone nodule

Goethite–hematite limonite concretion (FeO(OH), Fe₂O₃, and hydrated iron oxides)

Conglomerate

Clastic Sedimentary Rock (Conglomerate)

Man-made Synthetic Material (Plastic/Composite)

Acrylonitrile Butadiene Styrene (ABS) or High-Impact Polystyrene (HIPS)

Sea Glass

Man-made vitreous material / Silicon dioxide

Pyrite-bearing Schist

Metamorphic rock with FeS2

Felsic Drill Core (likely Gneiss or Granite)

Felsic Metamorphic Rock (Gneissic profile)

Blue Goldstone

Auraventurine (Synthetic glass with cobalt and copper inclusions)

Chert (Arrowhead Fragment)

Microcrystalline Quartz (SiO2)

Tumbled gray stone, likely quartz-rich pebble

Probable microcrystalline quartz/chalcedony (SiO₂), possibly gray jasper or quartzite

Costume Jewelry with Synthetic Gemstones

Synthetic Cubic Zirconia and Glass (SiO2 / ZrO2)

Sandstone Concretion

Limonitic Sandstone Concretion

Concretion

Sedimentary Concretion (Ironstone / Calcite Concretion)

Polymictic conglomerate or breccia (possibly concrete-like aggregate)

Lithified polymictic gravel; clasts may include basalt, granite, quartzite, and other silicates

Sandstone Concretion

Clastic Sedimentary Concretion (SiO2 with Iron Oxide)

Sandstone Concretion

Sedimentary Clastic Rock (Silicate-rich)

Not a rock, mineral, or geological specimen

Chakra Stone (Composite / Man-made Bonded Gemstones)

Composite of Quartz, Lapis Lazuli, Aventurine, Tiger's Eye, and Jasper (SiO2, (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, etc.)