Rock

Sandstone

Arenite

Quartzite Pebbles

Quartzite (SiO2 silicon dioxide dominant)

Greenstone with Quartz Veining

Epidiorite or Metabasalt with SiO2 (Quartz) veins

Quartz (Common Milky Quartz)

Silicon Dioxide (SiO2)

Granite Cobble

Phaneritic Felsic Igneous Rock (Granite)

Riverstone Quartzite (Water-worn Siltstone/Quartzite)

Metamorphosed Quartz-rich Arenite (SiO2)

Epidote

Epidote ({Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))

Ferruginous Chert

Silicon dioxide with iron oxide impurities (SiO2 + Fe2O3)

Chert Nodule

Chert (Cryptocrystalline variety of Quartz, SiO2)

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Ocean Jasper (Orbicular Jasper)

Silicon Dioxide (SiO2) - Variety of Chalcedony/Quartz

Red Sandstone (Iron-rich)

Ferruginous Sandstone (variable formula, primarily SiO2 + Fe2O3)

Red Sandstone (Iron-Rich)

Arenite (Fe2O3)

Pink Granite

Phaneritic Felsic Igneous Rock (Granite)

Sandstone (Ferruginous)

Arenite with Iron-Oxide Cement (primarily SiO2 with Fe2O3/FeOOH)

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Pink Granite

Granite (Phaneritic Quartz-Feldspar Rock)

Red Jasper (Brecciated or Mottled)

Silicon Dioxide (SiO2) with iron oxide inclusions

Jasper (Iron-stained Quartz)

Silicon dioxide (SiO2) with iron oxide inclusions

Amethyst (Chevron or Banded Amethyst)

Silicon Dioxide (SiO2) with iron impurities

Andesite Porphyry

Porphyritic Andesite

Sandstone (Micaceous)

Arenite (composed primarily of SiO2)

Black Veined Jasper (Spiderweb Jasper)

Silicon Dioxide (SiO2)

Ferruginous Sandstone (Ironstone)

Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)

White Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Sandstone (with Iron Oxide)

Arenite with Limonite/Hematite staining

Chert (Flint variety)

Chert (SiO2)

Brachiopod Fossil (Spiriferid)

Order Spiriferida (Phylum Brachiopoda); mineralized as Calcite (CaCO3) or Chert (SiO2)

Carnelian

Carnelian (SiO2, Silicon Dioxide with Iron Oxide impurities)

Honeycomb Coral Fossil

Favosites (extinct genus of tabulate coral)

Yellow Chert (Gold-toned Jasper)

Silicon Dioxide (SiO2)

Foliated Gneiss (River-Worn Pebble)

Gneiss (High-grade Regional Metamorphic Rock)

Iron Meteorite (likely Chondrite or weathered Iron-Nickel)

Meteorite (Fe-Ni alloy & silicates)

Yellow Quartzite

Quartzite (primarily SiO2)

Sandstone

Arenite (Siliclastic sedimentary rock), SiO2 + various minerals

Limestone

Calcium Carbonate (CaCO3)

Shale

Fissile mudstone (rich in clay minerals and quartz)

Limestone

Calcium Carbonate (CaCO3)

Jasper and Quartz River Cobble

Silicon Dioxide (SiO2) with Hematite inclusions

Limestone

Calcium Carbonate (CaCO3)

Basalt with Olivine Phenocrysts

Porphyritic Basalt (containing Mg2SiO4 - Fe2SiO4)

Sandstone (specifically Arkose or Quartz Arenite)

Arenite (primarily SiO2 with possible Feldspar)