Rock (Likely Sedimentary)

Vesicular basalt

Basalt, typically composed of plagioclase feldspar, pyroxene, and minor olivine or iron oxides

Orange Quartz (or Carnelian Chalcedony)

Silicon Dioxide (SiO2)

Granite

Phaneritic plutonic igneous rock (SiO2 range 65-75%)

Banded Gneiss (with Quartz Vein)

Gneiss (SiO2 and varied Silicates)

Yellow Chalcedony (Agate Pebble)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Chalcedony (Agate/Chert variety)

Silicon Dioxide (SiO₂)

Quartzite Pebble

Metamorphic rock primarily composed of Silicon Dioxide (SiO2)

Fossilized Gastropod in Chert/Limestone

Internal mold of Gastropoda (Class) with CaCO3 or SiO2 mineral formula

Yellow Agate (Banded Chalcedony)

Silicon Dioxide (SiO2)

Chert Breccia

Brecciated Chert (Microcrystalline SiO2)

Dyed or color-enhanced agate/microcrystalline quartz bead

Chalcedony (microcrystalline SiO₂), likely agate

Yellow Quartz Pebble (Citrine or Iron-Stained Quartz)

Silicon Dioxide (SiO2)

Red Garnet

Garnet Group (e.g., Pyrope, Almandine, Spessartine, Grossular, Andradite, Uvarovite)

Serpentinized ultramafic rock with magnesite

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

Jasper with Chert

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Polished agate/jasper nodule

Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide impurities

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Wishing Stone (Quartz-veined Metamorphic/Sedimentary Rock)

Quartz Vein in Greywacke/Slate (SiO2 in host rock)

Chalcedony (Carnelian Agate pebble)

Silicon Dioxide (SiO2)

Chalcedony (Commonly known as Carnelian or Agate pebble)

Microcrystalline Quartz (SiO2)

Quartz-rich granite or pegmatitic rock

Granite/pegmatite; chiefly quartz (SiO₂), feldspar, and minor mica

Pink Granite

Phaneritic intrusive igneous rock (rich in Potassium Feldspar)

Sandstone

Arenite (primarily SiO2)

Fossilized Wood (Petrified Wood)

Agatized wood (primarily SiO2)

Weathered iron-rich concretion (probable limonite/goethite)

Limonite–goethite aggregate, approximately FeO(OH)·nH₂O

Yellow Quartzite (Iron-stained)

Quartzite (primarily SiO2 with Fe2O3 staining)

Likely gray granite fragment

Granite, composed mainly of quartz, feldspar, and mica

Quartzite Pebble (with Iron Inclusions)

Quartzite (primarily SiO2 with Fe2O3/FeOOH impurities)

Likely galena-bearing ore

Galena (lead sulfide, PbS), possibly mixed with sulfide minerals

Sandstone

Clastic sedimentary rock (primarily SiO2)

Pegmatitic quartz–feldspar rock with mica

Granitic pegmatite; mainly quartz (SiO₂), feldspar, and biotite/muscovite mica

Pink Granite

Phaneritic Igneous Rock (high K-feldspar content)

Blue-and-gold lapis lazuli fragment

Lapis lazuli; lazurite-rich calc-silicate rock (primarily lazurite, with calcite and pyrite)

Fossilized ammonite (likely weathered ammonite cross-section)

Ammonoidea; commonly Jurassic–Cretaceous ammonite fossils replaced by calcite or aragonite

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Jasper or Chert with Quartz Vugs

Silicon Dioxide (SiO2)

Weathered iron-rich rock, possibly laterite or altered basalt

Probable ferruginous basalt/lat eritic material; exact identification requires testing

Limonite (Ironstone)

Limonite (mixture of hydrated iron(III) oxide-hydroxides)

Sandstone

Arenite (SiO2 based)

Mica-rich granite (likely biotite granite)

Biotite granite; mainly quartz (SiO₂), alkali/feldspar, and biotite mica

Quartz-rich rock with chlorite/epidote vein

Milky quartz with green chlorite or epidote; exact identification requires testing

Vesicular volcanic rock, possibly weathered basalt or scoria

Basaltic scoria/vesicular basalt; predominantly plagioclase, pyroxene, and iron-titanium oxides