Anthropogenic (Man Made Material)

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Chert (River Pebble)

Microcrystalline silica (SiO2)

Chert

Chert (SiO2)

Seashell Fragment

Calcium Carbonate (CaCO3) in the form of Aragonite or Calcite

Painted Pet Rock (Quartzite/Sandstone base)

Silicon Dioxide (SiO2) with anthropomorphic acrylic embellishments

Chert (specifically Red Chert/Jasper)

Microcrystalline Quartz (SiO2)

Chert (Red Jasper variant)

Microcrystalline Quartz (SiO2)

Ferruginous Quartz

Iron-stained Quartz (Silicon Dioxide, SiO2 with Fe2O3 inclusions)

Fossilized Bone

Permineralized Vertebrate Bone

Chert

Microcrystalline Quartz (SiO2)

Green aventurine beads

Quartz (SiO₂), typically green quartzite/aventurine with fuchsite mica inclusions

Limestone

Calcium Carbonate (CaCO3)

Polished ocean jasper / brecciated jasper

Jasper, microcrystalline quartz (SiO₂), with iron-oxide and other silicate inclusions

Likely dark rounded pebbles

Indeterminate; possibly basalt or a dark mafic mineral such as hornblende/biotite

Weathered chert or flint nodule

Microcrystalline quartz (SiO₂), commonly with chalcedony and minor iron oxides

Polished orbicular jasper (likely ocean jasper)

Silicified volcanic rock; chiefly microcrystalline quartz (SiO₂), with feldspar and iron-rich alteration minerals

Tumbled green aventurine (likely)

Quartz, SiO₂, containing green fuchsite mica or other inclusions

Red Sandstone (Iron-Rich)

Arenite (Fe2O3)

Weathered quartz-rich sandstone or granitic rock

Indeterminate; likely iron-stained quartz sandstone, possibly weathered granite

Iron-stained garnet-bearing rock, possibly almandine garnet

Garnet-group silicate, likely almandine (Fe₃Al₂Si₃O₁₂), in a quartz–iron-oxide matrix

Iron-rich weathered rock, likely limonite/goethite-bearing laterite

Limonite (variable hydrated iron oxides; chiefly goethite, α-FeO(OH))

Polished orbicular stone, likely granite or diorite

Granite–diorite, composed mainly of feldspar, quartz, and dark amphibole/biotite

Devil's Toenail

Gryphaea (extinct genus of foam oysters, typically composed of Calcite CaCO3)

Conglomerate

Conglomerate (Sedimentary Clastic Rock)

Tumbled granite or granitic gneiss

Granite, typically quartz + feldspar + mica; possibly foliated granitic gneiss

Mammoth or Mastodon Tooth Fossil

Proboscidea tooth (Mammuthus or Mammut)

Chert (varieties include Flint and Jasper)

Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)

Tumbled carnelian agate (probable)

Cryptocrystalline quartz, SiO₂; chalcedony variety colored by iron oxides

Limestone

Calcium Carbonate (CaCO3)

Chert (Quartz Variety)

Silicon Dioxide (SiO2)

Diabase

Diabase (also known as Dolerite)

Limestone

Calcium Carbonate (CaCO3)

Granite

Phaneritic Felsic Igneous Rock

Lava Rock (Basalt)

Basalt (extrusive igneous rock)

Granite

Phaneritic Felsic Igneous Rock (Granite)

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Dark fine-grained rock, likely basalt

Basalt; chiefly plagioclase feldspar and pyroxene, commonly with olivine and iron oxides

Red Sandstone

Ferruginous Sandstone

Polished/tumbled brown jasper or iron-rich chert

Microcrystalline quartz (SiO₂), commonly colored by hematite/goethite

Polished orbicular jasper

Silica-rich microcrystalline quartz/chalcedony (SiO₂), with iron oxides and green alteration minerals

Tumbled sandstone pebble

Quartz-rich sandstone, commonly subarkose or arkose

Weathered brown mineralized rock

Likely iron-stained quartzite or quartz-rich metamorphic rock; exact identification requires testing