Rock (Likely Sedimentary)

Honey calcite (likely rough cleavage fragment)

Calcite, calcium carbonate (CaCO₃)

Conglomerate

Sedimentary Conglomerate with Basaltic Clast

Sandstone (likely with Quartz Veining)

Arenite (primarily SiO2)

Likely weathered quartz-bearing rock (uncertain identification)

Possibly quartz-rich granite or granitic aplite; exact identification requires a clearer, larger image and tests

Chert with Limestone

Silicon Dioxide (SiO2) in Calcium Carbonate (CaCO3) Matrix

Chert / Quartz Pebble

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Rounded dark pebble, likely basaltic andesite

Fine-grained mafic volcanic rock; probable basalt or andesite, identification uncertain from image alone

N/A (Non-Geological Specimen)

Likely chert or flint

Microcrystalline quartz (SiO₂), commonly called chert; exact identification requires testing

Siltstone with Quartz Vein

Siltstone (primarily SiO2, Al2O3, Fe2O3)

Gneiss (Metamorphic Cobble)

Gneiss (High-grade Regional Metamorphic Rock)

Sandstone (likely Iron-rich or Arkosic)

Arenite (SiO2 with FeO(OH) or Fe2O3 staining)

Amethyst Geode

Silicon Dioxide with trace inclusions of Iron (SiO2)

Banded gneiss pebble

Gneiss, commonly quartz–feldspar–mica gneiss

Weathered sandstone cobble

Quartz-rich sandstone, primarily SiO₂ with clay/iron-oxide cement

Fossiliferous Shale or Slate with Plant Fossils

Fossil-bearing argillaceous rock

Sandstone

Arenite (primarily SiO2 with iron oxide cementation)

Weathered sandstone or granitic rock fragment

Likely quartz-rich sandstone; exact identification requires testing

Quartz-bearing metamorphic rock, likely garnet-mica schist

Quartz–mica schist with probable garnet and iron-oxide minerals

Almandine Garnet in Matrix

Almandine (Fe3Al2(SiO4)3)

Quartz (Smoky/Granular variety)

Silicon Dioxide (SiO2)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 cement)

Sandstone (likely Ferruginous)

Arenite (SiO2 with iron oxide impurities)

Quartz Geode Pebble

Silicon Dioxide (SiO2)

Brecciated quartz-rich rock, possibly silicified breccia

Silica-rich breccia; chiefly microcrystalline quartz (SiO₂), with possible calcite and iron-oxide staining

Gneiss

Foliated Metamorphic Gneiss

Garnet-Mica Schist

Garnetiferous Porphyroblastic Schist

Fossiliferous Chert or Limestone

Sedimentary rock containing fossilized marine invertebrates (likely crinoid stems or bryozoans)

Polished red jasper

Jasper, microcrystalline quartz (SiO₂) colored by iron oxides

Brachiopod Fossil in Limestone

Phylum Brachiopoda (likely Order Spiriferida), CaCO3 (Calcite)

Small rounded pebble

Indeterminate lithic grain; likely weathered sandstone, iron-stained quartz-rich rock, or a concretion

Weathered schist or foliated metamorphic rock

Mica schist, possibly phyllite; exact identification requires a fresh surface and testing

Chert (potentially Fossiliferous or Jasperoid)

Microcrystalline Quartz (SiO2)

Fossiliferous Chert

Silicon Dioxide (SiO2) with fossil inclusions

Sandstone (Quartzose)

Arenite (primarily SiO2)

Mixed stream gravel and common rock specimens

Predominantly quartz-rich granitoid, quartzite, sandstone, shale/slate, and mafic volcanic fragments; exact species cannot be determined confidently from the image

Conical fossil shell or shell fragment

Likely a gastropod shell fragment; exact taxon indeterminate from the image

Weathered sandstone or arkosic sandstone

Clastic sandstone, likely quartz–feldspar-rich (arkose)

Banded Sandstone

Arenite (composed primarily of Quartz: SiO2)

Sandstone (likely Graywacke or Arkose)

Clastic Sedimentary Rock (primarily SiO2 with various lithic fragments)

Jasper (likely Brecciated or Multi-colored)

Jasper (SiO2)

Sandstone (likely Arkosic or Lithic)

Clastic Sedimentary Rock (SiO2 with accessory minerals)