Mixed

Banded River Cobble with Mafic Dike

Hydrothermally altered Graywacke or Sandstone with Mafic Intrusion

Unakite

Unakite (altered granite)

Azurite Malachite

Azurite (Cu3(CO3)2(OH)2) and Malachite (Cu2CO3(OH)2)

Conglomerate

Conglomerate (clastic sedimentary rock)

Mixed River Stones and Agates

Mixed Silicates and Ironstones (primarily SiO2 and Fe2O3)

Leopard Skin Jasper

Silicon Dioxide (SiO2) with mineral inclusions

Granite Pebble

Granite

Black Tourmaline

Schorl (NaFe2+3Al6(Si6O18)(BO3)3(OH)4)

Graywacke

Graywacke Sandstone

Fuchsite

Chromium-bearing Muscovite [K(Al,Cr)2(AlSi3O10)(OH)2]

Barite

Barium Sulfate (BaSO4)

Gold and Silver (Metal Components of an Antique Pocket Watch)

Native Gold (Au) and Native Silver (Ag)

Granite Pebble (Pegmatitic Quartz-Feldspar River Rock)

Granite / Quartz-Feldspar-Mica Aggregate

Amethyst (Chevron or Banded Amethyst)

Silicon Dioxide (SiO2) with Fe3+ impurities

Red Granite

Granite (Felsic Plutonic Rock)

Fossiliferous Shale Matrix

Clastic Sedimentary Rock with Brachiopod or Mollusk shell fragments

Asphalt (Bituminous pavement)

Bituminous concrete / Asphalt

Granite Pebble

Granite (composed primarily of Quartz, Potassium Feldspar, Plagioclase, and Biotite/Amphibole)

Chrysocolla

Hydrated copper silicate, (Cu,Al)2H2Si2O5(OH)4·nH2O

Granite Pebble

Intrusive Igneous Rock (Quartz, Feldspar, Mica)

Unakite

Unakite Epidosite (composite of Epidote, Orthoclase, and Quartz)

Pink Granite

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

Granodiorite (Weathered)

Granodiorite

Granodiorite (containing Biotite and Quartz)

Granodiorite (Plagioclase-rich phaneritic intrusive rock)

Glauconitic Sandstone (Greensand)

Glauconitic Quartz Arenite (Formula: (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)

Sandstone (likely Greywacke or Siltstone variety)

Arenite / Siltstone (primarily SiO2)

Unakite

Unakite (metamorphosed granite)

Lepidolite in Quartz

K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2 / SiO2

Azurite-Malachite with Limonite

Cu3(CO3)2(OH)2 (Azurite) / Cu2CO3(OH)2 (Malachite)

Purple Lepidolite with Quartz

Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)

Gravel / Crushed Stone

Aggregate (mixed mineral rock fragments)

Unakite

Altered Granite (Epidotized Granite)

Bauxite (Iron-stained Chert / Ironstone Aggregate)

Hydrous aluminum oxide mixture (mainly Gibbsite Al(OH)3, Boehmite γ-AlO(OH), and Goethite α-Fe3+O(OH))

Yellow Jasper

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Devil's Toenail (Fossil Oyster)

Gryphaea arcuata (Calcium Carbonate, CaCO3)

Gravel and Pebbles

Unconsolidated rock fragments (clastic sediment)

Chrysocolla in Quartz

Hydrated copper phyllosilicate with silicon dioxide (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O + SiO2)

Chrysocolla

Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O

Mookaite Jasper

Silicified radiolarite (SiO2)

Mookaite Jasper

Silicified Radiolarite (SiO2)

Amethyst (Raw Quartz)

Silicon Dioxide (SiO2)

Unidentified coarse-grained rock fragments

Likely granite or granitic rock; exact identification is uncertain from the photograph