Rock (Likely Sedimentary)

Greenstone / altered basalt fragment

Likely chlorite–epidote–actinolite altered basalt; exact identification requires testing

Granite (likely biotite granite)

Granite; primarily quartz, feldspar, and biotite mica

Quartz (Druzy)

Silicon Dioxide (SiO2)

Coal

Bituminous or sub-bituminous coal (carbonaceous rock)

Brecciated jasper/chalcedony

Silica-rich breccia composed mainly of microcrystalline quartz (SiO₂), with iron-oxide and possibly epidote or chlorite inclusions

Sandstone

Arenite (predominantly SiO2 with iron oxides)

Chert

Chert (Microcrystalline Quartz)

Quartz Pebble (Chert/Chalcedony)

Silicon Dioxide (SiO2)

Turquoise (likely stabilized or simulated Howlite)

CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)

Sandstone Pebble

Sandstone (Silicon dioxide-rich clastic sedimentary rock)

Chert (specifically Flint or Jasper variant)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Sandstone with Iron Banding

Arenite with Hematite or Limonite staining (SiO2 with Fe2O3)

Quartz crystal pendant

Quartz (silicon dioxide, SiO₂), likely rock crystal or milky quartz

Milky Quartz with Mineral Inclusions

Quartz (Silicon Dioxide - SiO2)

Tumbled granite (likely black granite)

Granite; predominantly quartz (SiO₂), feldspar, and biotite/hornblende

Tumbled chalcedony (likely gray/brown agate)

Microcrystalline quartz, SiO₂ (chalcedony; possible agate variety)

Sandstone Pebble

Sedimentary Rock (Quartzose Sandstone)

Fossilized Bivalve Shell

Class Bivalvia (fossilized)

Fossil Shark Tooth

Selachii (fossilized dentition)

Weathered quartz-rich rock, possibly milky quartz or quartz-bearing granite

Quartz (SiO₂), potentially with feldspar and iron-oxide staining

Sandstone

Arenite (primarily SiO2)

Rounded brown pebble, likely chert or iron-stained quartzite

Chert (microcrystalline quartz, SiO₂) or quartzite (recrystallized quartz, SiO₂)

Porphyritic rhyolite (likely lithophysal/vesicular rhyolite)

Rhyolite; chiefly quartz and alkali feldspar, with minor plagioclase and iron-bearing minerals

Granite

Felsic Plutonic Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)

Chert (v. Flint)

Sedimentary Cryptocrystalline Quartz (SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Zebra Jasper

Silicon Dioxide (SiO2) - Macro-crystalline Quartz/Chert with impurities

Chert Pebble

Chert (Microcrystalline Quartz, SiO2)

Sandstone with Quartz Vein

Arenite with SiO2 intrusion

Shale

Lutaceous Rock (Hydrous Aluminum Silicates)

Granite Pebble

Intrusive Felsic Igneous Rock (primarily SiO2 with Al2O3, K2O, Na2O)

Travertine (or Calcareous Tufa)

Calcium Carbonate (CaCO3)

Amygdaloidal Basalt

Basalt with secondary amygdule minerals (likely Epidote or Chlorite)

Conglomerate

Conglomerate (a clastic sedimentary rock)

Chert (Flint)

Silicon Dioxide (SiO2)

Shark Tooth Fossil

Otodus sp. (possibly Cretalamna)

Porphyritic Basalt (Peanut Obsidian/Star Galaxy-style)

Porphyritic Basalt (Silica-rich Volcanic Rock)

Granite

Phaneritic intrusive igneous rock (primarily SiO2)

Chert (Jasper nodule)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Sandstone

Arenite (composed primarily of SiO2)

Crinoid and Coral Fossils in Limestone

Fossiliferous Limestone with Rugosa (order) and Crinoidea (class)

Chert (often called Flint when dark or worked)

Cryptocrystalline silica (SiO2)