Organic Material (Likely A Fruit Or Berry)

Chert (likely flint)

Microcrystalline quartz (SiO₂), chiefly chalcedony and quartz

Polished banded agate (likely picture jasper or petrified wood)

Microcrystalline quartz, SiO₂, with iron-oxide and clay inclusions

Petrified Wood

Silicified Wood (primarily SiO2)

Chert (Jasper variety)

Chert (Silicon Dioxide, SiO2)

Sedimentary Rock with Crafts (Pet Rock)

Sedimentary rock decorated with synthetic materials

Polished agate-like stone (uncertain; possibly a fossil or shell fragment)

Likely microcrystalline quartz (chalcedony), SiO₂; exact identification is limited by the image

Carved pyrite frog or toad

Pyrite (iron disulfide, FeS₂), likely a carved massive aggregate

Chert (Yellow/Tan Variety)

Chert (SiO2)

Tumbled moss agate (likely)

Chalcedony, microcrystalline quartz (SiO₂), with iron/manganese inclusions

Fossiliferous Siltstone

Clastic Sedimentary Rock with Fossil Inclusions

Sandstone (with carbonaceous plant fragments)

Arenite (composed primarily of SiO2)

Chert (Nodule)

Microcrystalline or Cryptocrystalline Silica (SiO2)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Tumbled chert or flint pebble

Microcrystalline quartz (SiO₂), likely chert; exact variety uncertain from the image

Chert (Nodule / Geode fragment)

Microcrystalline Quartz (SiO2)

Petrified Wood

Silicified Wood (primarily SiO2)

Petrified Wood

Silicified Wood (primarily Quartz or Chalcedony, SiO2)

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Potassium-Rich Silicate Clay (inferred from biological context)

Phyllosilicate group (likely Illite or Smectite within surrounding soil substrate)

Sandstone (likely Arkose or Quartz Sandstone)

Arenite (SiO2 principal component)

Chert (Jasper/Flint variety)

Silicon Dioxide (SiO2)

Fossil bone or tooth fragment

Indeterminate fossilized vertebrate bone/tooth; taxonomic identification is not possible from this blurred image

Chert (Arrowhead or Projectile Point)

Microcrystalline or Cryptocrystalline Quartz (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

Fossiliferous limestone (likely ammonite/gastropod-bearing)

Bioclastic limestone; predominantly calcite (CaCO₃)

Yellow Chert (Jasper)

Cryptocrystalline Quartz (SiO2)

Petrified Wood

Silicified Wood (primarily SiO₂)

Chert (Flint)

Chert (Microcrystalline Quartz, SiO2)

Beach sandstone or cemented beachrock fragment

Lithified carbonate- or silica-rich sand; commonly calcarenite or quartz sandstone

Weathered fossilized wood (likely petrified wood)

Silicified wood; commonly quartz/chalcedony replacing wood tissue (SiO₂)

Polished ornamental jasper (likely Peanut Wood or similar brecciated jasper)

Microcrystalline quartz/chalcedony (SiO₂), with iron-oxide and clay inclusions

Banded agate (likely petrified wood or silicified sediment)

Microcrystalline quartz/chalcedony, SiO₂; possible silicified wood

Tumbled amber-colored pebble

Likely quartz/chert or iron-stained chalcedony; exact identification requires testing

Fossilized Wood (Petrified Wood)

Agatized wood (primarily SiO2)

Fossil-bearing ironstone or weathered concretion

Indeterminate; likely ferruginous sandstone/concretion containing a partial fossil impression

Chert (specifically a nodule with Chalcendony/Agate banding)

Microcrystalline Quartz (SiO2)

Chert (likely brown flint)

Microcrystalline quartz, SiO₂ (chalcedonic quartz aggregate)

Fossiliferous shale or slate with plant impressions

Carbonaceous mudstone/shale; possible fossil plant material (often fern-like impressions)

Chert (Nodule/Pebble)

Chert (Silicon Dioxide, SiO2)

Fossil mammalian skull

Fossilized vertebrate bone; exact taxon cannot be determined from the image

Iron-stained quartz-rich rock, possibly jasper or chert

Microcrystalline quartz (SiO₂) with iron oxides/hydroxides

Fossilized coral or silicified organic limestone

Likely fossil coral (Scleractinia/Tabulata) replaced or cemented by calcite and silica; exact identification requires close examination