Anthropogenic (Man Made)

Likely milky quartz fragment

Quartz (SiO₂)

Small rounded pebble (rock type indeterminate)

Unidentified fine-grained lithic pebble

Milky quartz pebble

Quartz (silicon dioxide, SiO₂)

Colorless faceted gemstone, likely quartz

Quartz (SiO₂), tentative identification; the photo is insufficient to confirm the material

Milky quartz pebble

Quartz, silicon dioxide (SiO₂)

Goldstone (likely blue-free synthetic goldstone pendant)

Synthetic aventurine glass; silica glass with dispersed metallic copper crystals

Red cabochon gemstone ring (likely glass or synthetic stone)

Undetermined; the image does not establish a natural mineral identity

Brown chert (flint)

Microcrystalline quartz (SiO₂), varieties called chert or flint

Polished greenstone/serpentine pebble (probable)

Serpentinite, dominated by serpentine-group minerals (lizardite/chrysotile); possible accessory olivine or chlorite

Bivalve shell fossil or modern shell

Calcareous bivalve shell, composed mainly of calcium carbonate (typically aragonite and/or calcite); species cannot be determined from this view

Chert (possibly a worked stone flake)

Microcrystalline quartz, SiO₂

Blue glassy cabochon, likely blue quartz or synthetic glass

Possibly dyed blue chalcedony/quartz (SiO₂); visual identification is inconclusive

Basalt

Basalt

Blue tumbled glass or dyed stone (uncertain)

Unidentified; appearance is consistent with blue glass, but a blue mineral such as dyed quartz cannot be ruled out from the photo

Beaded mineral/crystal jewelry (likely turquoise and coral accents)

Variable; blue beads may be turquoise (CuAl6(PO4)4(OH)8·4H2O), with possible dyed howlite, glass, or composite materials

Paving-concrete aggregate with a rounded stone

Polymictic gravel aggregate; the central clast appears to be weathered sandstone or volcanic rock

Quartz geode with druzy crystals

Quartz (SiO₂), likely with iron-oxide staining and darker host rock

Yellow chalcedony (likely agate) cabochons

Microcrystalline quartz, SiO₂; chalcedony variety, possibly naturally colored or dyed

Granite

Granite (plutonic igneous rock)

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

Microcrystalline quartz (SiO₂) with iron oxides/hydroxides

Flint or chert, possibly a knapped stone tool

Microcrystalline quartz (SiO₂), commonly chalcedony with possible carbonaceous impurities

Sandstone

Arenite (composed primarily of Quartz: SiO2)

Carved yellow stone butterfly

Undetermined; possibly carved soapstone (talc-rich rock) or another soft ornamental stone

Fossilized echinoid (sea urchin), likely a flint/chalk-associated test

Echinoid fossil; likely a regular echinoid such as Echinocidaris or related taxon, composed mainly of recrystallized calcite (CaCO₃)

Diabase (Dolerite)

Diabase / Dolerite

Land Snail Shell

Gastropoda (Calcium Carbonate, CaCO3)

Blue glass-like tumbled specimen

Most likely cobalt-blue slag glass or manufactured glass; not confidently identifiable as a natural mineral from the image

Sandstone

Arenite

Pale green aventurine (likely quartz) sphere

Quartz, SiO₂; possibly pale green aventurine, with color from inclusions or treatment

Dark quartz point (possibly smoky quartz)

Quartz, SiO₂; the dark color may indicate smoky quartz, but the image is insufficient to confirm

Quartzite

Metamorphic Quartz Sandstone

Quartzite

Metamorphic Quartzite (SiO2)

Red Sandstone

Arenite (Ferruginous Sandstone)

Quartzite

Metamorphic Quartzite (SiO2)

Sandstone (Pebble)

Sandstone (arenite, arkose, wacke depending on composition)

Jasper

Silicon dioxide (SiO2) with impurities

Quartzite

Metamorphic Rock (Mainly SiO2)

Obsidian (Black)

Obsidian (High-silica volcanic glass)

Diabase (Greenstone)

Diabase (Dolerite)

Fossil crinoid columnal in limestone

Crinoidea indet.; calcitic ossicle (CaCO₃)

Likely flint pebble (possibly a worked flint fragment)

Microcrystalline quartz (chalcedony), SiO₂; commonly called flint

Sandstone

Arenite