Rock (Likely Sedimentary)

Granite (likely a river or beach pebble)

Granite (a felsic intrusive igneous rock primarily composed of quartz, feldspar, and mica)

Quartz crystal (likely milky quartz)

Quartz, silicon dioxide (SiO₂)

Graphite

Graphite (Native Carbon, C)

Blue slag glass or dyed glass-like industrial material

Amorphous silicate glass; likely copper-bearing blue slag, but possibly colored man-made glass

River Cobble (likely Quartzite or Sandstone)

Silicon dioxide (SiO2)

Agate

Silicon dioxide (Chalcedony), SiO2

Speckled granitic rock

Likely granite or granodiorite; quartz–feldspar–mica aggregate

Weathered granite or granitic gneiss

Granite; mainly quartz (SiO₂), feldspar, and mica

Quartz Crystal Cluster

Quartz (Silicon Dioxide, SiO2)

Black Granite (likely Gabbro or Dolerite)

Phaneritic Mafic Igneous Rock (plagioclase and pyroxene)

River Cobble (likely Basalt or Greenstone)

Mafic Igneous Rock (with possible chloritic alteration)

Gabbro (likely with Pyrite/Sulfide mineralization)

Mafic Intrusive Igneous Rock

Fossiliferous Sandstone / Fossil Fragment

Fossiliferous Sedimentary Matrix with Indeterminate Fossil Material

Likely fossilized shell or carbonate concretion

Indeterminate biogenic calcium carbonate, commonly calcite (CaCO₃)

Agate (specifically Moss or Plume Agate nodding toward Agatized Wood)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz (Chalcedony)

Banded Agate (with small Geode cavity)

Silicon Dioxide (SiO2) - Chalcedony variety

Weathered iron-rich sandstone or ironstone

Ferruginous sandstone, likely limonite/goethite-cemented quartz arenite

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Chert (with Calcite Veining)

Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3) veins

Chalky limestone

Micritic calcite limestone; predominantly CaCO₃

Honey calcite (likely cleavage fragment)

Calcite, CaCO₃

Chert (Arrowhead Fragment)

Silicon Dioxide (SiO2)

Ferruginous Sandstone (with possible trace fossils)

Arenite with Iron-Oxide Cement (SiO2 with Fe2O3)

Seashell Fossil

Invertebrate Bivalve / Gastropod Fossil (Calcium Carbonate, CaCO3)

Bivalve Shell (Fossil or Contemporary)

Class Bivalvie (various genera and species of clams, cockles, etc.)

Likely granite or granitic gneiss

Quartz–feldspar–mica aggregate; possibly foliated granitic gneiss

Snakeskin Jasper

Microcrystalline Quartz (SiO2) with iron inclusions

Pink Granite

Phaneritic Felsic Igneous Rock (composed primarily of K-Feldspar, Quartz, and Mica)

Sandstone (with Iron Staining)

Clastic Sedimentary Rock (primarily Quartz, SiO2)

Red cabochon gemstone, likely carnelian

Carnelian: orange-red chalcedony, microcrystalline quartz (SiO₂)

Fossilized Bone Fragment

Permineralized Skeletal Element (Likely Vertebrate)

Chert (Arrowhead)

Chert (primarily Microcrystalline Silica, SiO2)

Red Sandstone

Arenite (Iron-rich)

Petrified Wood

Silicified wood (Quartz/Chalcedony/SiO2)

Silicified fossil-bearing limestone (likely chert/agate replacement)

Microcrystalline quartz (SiO₂) replacing carbonate rock; possible fossiliferous limestone

Pyrite in Shale

Iron Disulfide (FeS2) in Sedimentary Shale

Petrified Wood

Silicified Wood (SiO2)

Dark glassy pebble, possibly volcanic rock

Likely basalt or volcanic glass (var. obsidian), unconfirmed from image

Fossilized Brachiopod

Brachiopoda (likely Order Spiriferida or Productida)

Sulfide Ore (likely Galena and Sphalerite in Quartz)

Lead-Zinc Ore (PbS and ZnS)

Granite pebble

Granite; chiefly quartz, potassium feldspar, plagioclase, and minor biotite/hornblende