Sedimentary (Microcrystalline Silicate)

Banded Iron Formation (BIF)

Banded Iron Formation (predominantly Hematite Fe2O3 and Magnetite Fe3O4 with Chert SiO2)

Banded Gneiss

Gneiss (high-grade metamorphic silicate rock)

Rounded gray pebble, possibly limestone or quartzite

Uncertain; likely micritic limestone (calcite, CaCO₃) or fine-grained quartzite (quartz, SiO₂)

Coprolite

Fossilized feces (various taxa)

Sandstone (Ferruginous)

Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 staining)

Weathered iron-rich rock, possibly limonite-bearing basalt or ironstone

Uncertain; likely Fe-oxide/hydroxide–stained mafic rock (hematite Fe₂O₃, goethite FeO(OH), and silicates)

Dark metamorphic rock, likely slate or phyllite

Foliated metapelite; commonly mica-rich quartz–clay mineral assemblage

Common Opal

Hydrated silica (SiO2 " nH2O)

Ferruginous Sandstone

Arenite with Iron Oxide cement (Fe2O3 / FeO(OH))

Sandstone (Ferruginous)

Arenite (Fe2O3 rich)

Sandstone (Quartzose Sandstone)

Arenite (primarily SiO2)

Unidentifiable embedded dark fragment

Indeterminate; possibly a dark silicate mineral or lithic inclusion

Rhodonite

Manganese Silicate (Mn,Fe,Mg,Ca)SiO3

Ferruginous Sandstone (with possible trace fossils)

Arenite with Iron-Oxide Cement (SiO2 with Fe2O3)

Polished orbicular jasper (likely ocean jasper)

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

Polished/tumbled jasper, likely ocean jasper or brecciated jasper

Jasper: microcrystalline quartz (SiO₂) with iron oxides and other silicate impurities

Chalky limestone

Micritic calcite limestone; predominantly CaCO₃

Smooth river pebble, likely quartz-rich sandstone or quartzite

Probable quartz arenite (sandstone) or quartzite; mainly SiO₂ with minor iron-bearing minerals

Green Jasper (or Moss Agate / Prase)

Silicon Dioxide (SiO2) with chlorite or amphibole inclusions

Moss Agate

Chalcedony (SiO2) with inclusions of hornblende or chlorite

Dalmatian Stone

Dalmatian Jasper / Feldspathic Igneous Rock

Rhodonite

Manganese Silicate (Mn,Fe,Mg,Ca)SiO3

Green Calcite

Calcium Carbonate (CaCO3)

Graphite-bearing schist (probable)

Graphite schist; chiefly quartz, mica, and graphite

Conglomerate

Conglomerate (SiO2 matrix with various silicate clasts)

Copper-bearing rock, likely native copper in matrix

Native copper (Cu), possibly with cuprite/iron-rich matrix

Likely weathered limestone fragment

Calcite-rich limestone (CaCO₃), possibly calcareous sandstone

Aragonite (Onyx Marble)

Calcium Carbonate (CaCO3), Orthorhombic crystal system

Weathered sandstone or limestone fragment

Likely quartz-rich sandstone or micritic limestone; exact identification requires testing

Banded iron formation (ironstone)

Banded iron formation, chiefly hematite/magnetite with chert (SiO₂)

Quartzite

Quartzite (SiO2)

Siltstone River Rock

Siltstone (composed of silt-sized particles, silicate minerals)

Red Sandstone

Arenite (Ferruginous Sandstone)

Sandstone (Ferruginous)

Arenite with Iron-Oxide cement

Sandstone (Ferruginous)

Arenite (with Iron Oxide cement)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 staining)

Tree Agate

Dendritic Agate (Silicon Dioxide, SiO2)

Gray foliated metamorphic rock, likely gneiss or schist

Quartz–feldspar–mica metamorphic rock; exact identification requires a fresh surface and testing

Mica / Muscovite or Biotite

Phyllosilicate mineral group (e.g., KAl2(AlSi3O10)(OH)2)

Greenstone / Glauconitic Siltstone

Metabasalt or Glauconite-rich Sedimentary Rock

Mixed rounded gravel and weathered rock fragments

Polymictic alluvial or glacial gravel; composition appears to include basaltic, quartz-rich, and feldspathic clasts

Unidentified greenish-gray rock fragment

Tentatively altered basalt or basaltic volcanic rock; mineral identification requires testing