Anthropogenic (Man Made Material)

Conglomerate

Conglomerate (Sedimentary Clastic Rock)

Heat-Treated Citrine

Silicon Dioxide (SiO2) with iron impurities

Petrified Wood

Silicified Wood (primarily SiO2)

Quartz / Limestone Gravel

SiO2 (Silicon Dioxide) and CaCO3 (Calcium Carbonate)

Dalmatian Jasper

Dalmatian Stone (a microcrystalline quartz and feldspar rock with arfvedsonite)

Amygdaloidal Basalt

Amygdaloidal Basalt containing Zeolite or Quartz (SiO2/Silicates)

Petrified Wood

Silicified Wood (SiO2)

Small rounded pebble, likely quartz-rich river stone

Indeterminate; likely quartz/chert-bearing lithic clast

Uncertain polymict breccia or altered volcanic rock

Likely hydrothermally altered volcanic breccia; exact mineral identification requires testing

Quartz-rich feldspathic pebble, possibly granite or granitic gneiss

Quartz–feldspar aggregate, likely granite; dark inclusion may be biotite, hornblende, or iron-oxide staining

Vesicular quartz-rich rock, possibly weathered rhyolite or hydrothermal quartz

Likely quartz (SiO₂) with altered feldspar, iron oxides, and cavities; exact identification requires testing

Likely weathered gray-green stone, possibly serpentinite

Serpentinite (predominantly serpentine-group minerals; identification uncertain from image)

Quartz-bearing granite or granitic pegmatite

Felsic intrusive rock, chiefly quartz (SiO₂), feldspar, and minor mica

Iron-rich quartzite or ironstone

Ferruginous quartzite; chiefly quartz (SiO₂) with iron oxides such as hematite and goethite

Quartz-bearing iron-stained breccia

Brecciated quartz/quartzite with iron oxides, chiefly SiO₂ with hematite/goethite and possible feldspar or host-rock fragments

Pale rounded quartz-rich pebble, likely quartzite

Quartzite (mostly microcrystalline SiO₂), possibly quartz-rich sandstone or vein quartz

Iron-rich sandstone or laterite

Ferruginous sandstone; mainly quartz (SiO₂) cemented or stained by iron oxides such as hematite (Fe₂O₃) and goethite (FeO(OH))

Weathered limestone or calcareous sandstone

Calcite-rich carbonate rock, chiefly calcium carbonate (CaCO₃), possibly fossiliferous limestone

Limestone

Calcium Carbonate (CaCO3)

Orbicular jasper / brecciated jasper

Silica-rich microcrystalline quartz (chalcedony), commonly with iron oxides and altered volcanic fragments

Dzi Bead (Agate Bead)

Cryptocrystalline Quartz (SiO2) - Chalcedony/Agate

Petrified Wood

Silicified Wood (primarily SiO2)

Chert (Yellow Jasper)

Microcrystalline Quartz (SiO2)

Jade

Jadeite or Nephrite

Petrified Wood (Agatized/Silicified Wood)

Silicified Wood (SiO2)

Conglomerate

Conglomerate (clastic sedimentary rock)

Petrified Wood

Silicified Wood (primarily SiO2)

Travertine

Calcareous Tufa / Travertine (CaCO3)

Beach Quartzite Pebble

Quartzite (primarily SiO2)

Petrified Wood

Silicified Wood (SiO2)

Tumbled red jasper

Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides

Fossil Coral

Rugose Coral / Hexagonaria (CaCO3)

Tumbled pegmatitic granite

Coarse-grained granite/pegmatite, chiefly quartz, feldspar, and biotite or amphibole

Chert (varietal: Jasper or Ironstone nodule)

Microcrystalline Quartz (SiO2) with iron oxides

Weathered limestone fragment

Calcitic limestone (mostly CaCO₃; possibly micritic limestone)

Chert (Fossiliferous)

Silicon dioxide (SiO2)

Serpentinized ultramafic rock with magnesite

Serpentinite, chiefly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), with likely magnesite (MgCO₃) and minor chromite/magnetite

Agate

Silicon Dioxide (Chalcedony), SiO2

Agate

Silicon Dioxide (Chalcedony), SiO2

Chert

Microcrystalline quartz (SiO2)

Flint

SiO2 (Microcrystalline Quartz / Chert)

Chert / Jasper

Silicon Dioxide (SiO2)