Rock (Likely Sedimentary)

Chert (with Quartz/Chalcedony)

Microcrystalline Quartz (SiO2)

White quartz pebble

Quartz (silicon dioxide, SiO₂), likely milky quartz

Small quartz-rich rock fragment (tentative)

Quartz, silicon dioxide (SiO₂), possibly in a feldspar-bearing granite fragment

Blue Dyed Agate Geode (Slice)

Silicon Dioxide (SiO2) - Chalcedony / Quartz

Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

Quartz (Gravel fragment)

Quartz (Silicon Dioxide, SiO2)

Pink Granite with Quartz Vein

Phaneritic Plutonic Felsic Rock (K-feldspar + Quartz + Plagioclase + Mica)

Blue Lace Agate (with Amethyst Geode center)

Silicon Dioxide (SiO2) - Cryptocrystalline Chalcedony

Weathered iron-stained quartzite or sandstone cobble

Quartzite (quartz-rich rock), possibly ferruginous sandstone

River Cobble (likely Serpentinite or Greenstone)

Serpentinite / Greenschist facies rock

Likely weathered basalt or mafic volcanic rock

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

Jasper (Green Jasper/River Stone)

Silicon Dioxide (SiO2) with impurities

Weathered quartz-rich pebble, possibly milky quartz or chalcedony

Quartz, SiO₂; exact variety uncertain from the image

Granite Cobble

Granite (Felsic Plutonic Rock)

Porphyritic Basalt (with Granite inclusion)

Porphyritic Mafic Volcanic Rock

Granite Cobble

Felsic Intrusive Igneous Rock

Rounded quartz-rich cobble

Likely quartzite or siliceous sandstone; predominantly microcrystalline SiO₂ with possible feldspar and iron-oxide staining

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Fossilized Shell Fragment

Bivalvia or Gastropoda (Class) fragment

Sandstone

Arenite (SiO2, often with CaCO3 or Fe2O3 cement)

Gneiss (Granitic Gneiss)

Gneiss

Jasper (Banded Jasper)

Silicon Dioxide (SiO2) with impurities

Iron-rich laterite or limonite/goethite-bearing rock

Hydrated iron oxides, chiefly goethite (α-FeO(OH)) and limonite (FeO(OH)·nH₂O), likely in a lateritic matrix

Milky quartz-rich rock

Quartz (SiO₂), likely massive milky quartz with minor iron-oxide staining and attached host material

Quartzite Pebble

Quartzite (SiO2)

Basalt with Plagioclase Porphyry

Porphyritic Basalt

Quartz Pebble

Silicon Dioxide (SiO2)

Quartzite (Iron-stained)

Quartzite (mostly SiO2 with Fe2O3 impurities)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz (Milky/Iron-stained)

Silicon Dioxide (SiO2)

Quartzite

Quartzite (primarily SiO2)

Chert (Jasper Variant likely)

Silicon Dioxide (SiO2)

River Cobble (likely Basalt or Chert)

Siliceous River Rock / Microcrystalline Quartz / Mafic Igneous

Granite Cobble

Plutonic Igneous Rock (Granitic)

Quartz with Iron Staining

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Milky Quartz (Common Quartz)

Quartz (Silicon Dioxide, SiO2)

Tumbled pegmatitic granite

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

Orbicular granite (likely larvikite/rapakivi-type granite)

Granite; chiefly quartz, alkali feldspar, plagioclase, with dark biotite/amphibole and iron-oxide veining

Sandstone with Quarzite clasts

Arenite (SiO2 based)

Sandstone

Arenite (primarily SiO2)