Sedimentary And Igneous (Mixed)

Orange Calcite

Calcium Carbonate (CaCO3)

Granitic Gneiss

Gneiss (High-grade Metamorphic Rock)

Schist

Mica Schist (Variable chemistry, often rich in muscovite and biotite)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

Gneiss

Gneiss

Gneiss (specifically a Banded Gneiss cobble)

Gneiss (composed mainly of Quartz, Feldspar, and Biotite/Amphibole)

Carnelian

Carnelian (SiO2, Silicon Dioxide with Iron Oxide impurities)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

K2 Jasper (K2 Granite)

Azurite in Granite (Biotite Granite with Azurite inclusions)

Granite

Granite (composed primarily of Quartz SiO2, Alkali Feldspar KAlSi3O8, and Plagioclase Feldspar)

Leopard Skin Jasper

Rhyolite (Silicon Dioxide with impurities), SiO2

Granite

Phaneritic Igneous Rock (Granite)

Rounded gray pebble

Indeterminate; likely a water-worn silicate or carbonate pebble

Yellow Quartz (Citrine/Yellow Jasper Pebble)

Silicon Dioxide (SiO2)

Conical fossil shell or shell fragment

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

Porphyritic basalt (likely amygdaloidal basalt)

Basalt, a mafic volcanic rock; composition typically plagioclase + pyroxene, with possible olivine and vesicle-filling minerals

Pebble

Clast (specifically a granule or small pebble)

Quartz Pebble

Silicon Dioxide (SiO2)

Likely weathered quartz-bearing rock (uncertain identification)

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

Quartz-bearing granite or granitic pegmatite

Felsic intrusive rock, chiefly quartz (SiO₂), feldspar, and minor mica

Wonderstone (Banded Rhyolite)

Rhyolite (Silicon Dioxide with Iron Oxide impurities)

Quartz River Cobble

Silicon Dioxide (SiO2)

Likely porphyritic igneous rock (possibly granite or rhyolite)

Quartz–feldspar–mica aggregate; exact identification requires a fresh surface and tests

Weathered basalt or mafic volcanic rock

Basalt; typically plagioclase feldspar, clinopyroxene, and often olivine or iron oxides

Granite Cobble

Phaneritic Felsic Igneous Rock (Granite)

Pyrite in Quartz Matrix

Iron Disulfide (FeS2) in Silicon Dioxide (SiO2)

Weathered limestone or calcitic cave deposit

Calcite (CaCO₃), likely porous limestone/travertine

Jasper

Silicon Dioxide (SiO2)

Dark gray volcanic rock, probably andesite or basalt

Fine-grained mafic–intermediate volcanic rock; likely basalt (plagioclase ± pyroxene), possibly andesite

Weathered reddish-brown rock fragment

Probably altered basalt or fine-grained volcanic rock; exact identification requires testing

Tumbled dark stone, likely basalt or chert

Basalt (fine-grained mafic rock), possibly weathered chert; exact identification requires testing

Milky Quartz (Druzy Geode fragment)

Silicon Dioxide (SiO2)

Amethyst

SiO2 (Silicon Dioxide)

Leopard Skin Jasper

Silicon Dioxide (SiO2) with impurities

Quartz

Silicon Dioxide (SiO2)

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Tumbled dark stone, possibly chert or basalt

Indeterminate; likely fine-grained basalt (plagioclase–pyroxene) or microcrystalline chert (quartz, SiO₂)

Biotite granite (weathered granitic rock)

Granite; chiefly quartz (SiO₂), feldspar, and biotite mica

Granite

Granite

Gneiss

Metamorphic rock (Gneiss)