Mixed: Igneous And Sedimentary

Pyrite

Iron Sulfide (FeS2)

Blue Chalcedony

Chalcedony (SiO2)

Quartz (Milky Quartz / Quartzite)

Silicon Dioxide (SiO2)

River Rock (Basalt/Greywacke)

Aphanitic Basalt or Lithic Sandstone (Greywacke)

Sandstone

Arenite (SiO2 principal)

Sandstone (Picture Sandstone)

Arenite (primarily SiO2)

Chert (Jasper/River Stone)

Silicon dioxide (SiO2) - Microcrystalline quartz

Ferruginous Chert

Microcrystalline Quartz (SiO2) with Iron Oxides

Banded Agate (River-worn Pebble)

Cryptocrystalline Silicon Dioxide (SiO2)

Green Moss Agate

Silicon Dioxide with inclusions (SiO2)

Red Jasper

Silicon Dioxide (SiO2) - variety of Chalcedony

Bumblebee Jasper

Volcanic Tuff (mixture of Quartz, Sulfur, Hematite, and Orpiment)

Labradorite (tumbled)

Labradorite (a plagioclase feldspar mineral between anorthite and albite; chemical formula: (Ca,Na)(Si,Al)4O8)

Sandstone (Ferruginous)

Sandstone (primarily SiO2 with Iron Oxide cement)

Clear Quartz (or Rock Crystal)

Quartz (SiO₂ - Silicon Dioxide)

Yellow Quartz (Citrine/Yellow Jasper mix)

Silicon Dioxide (SiO2)

Black Sand (Magnetite Sand)

Magnetite-rich Placers (Fe3O4)

Quartz River Pebbles

Silicon Dioxide (SiO2)

Yellow Jasper

Silicon Dioxide (SiO2)

Greenstone (Greywacke or Nephrite Jade variant)

Metamorphosed mafic igneous or sedimentary rock (e.g., Actinolite-Chlorite Schist)

Gneiss (Stream-worn Cobble)

Gneiss (Metamorphic rock composed primarily of Quartz, Feldspar, and Mica)

Carnelian

Carnelian (a variety of Chalcedony); SiO2 (Silicon Dioxide)

Chalcedony (Agate/Chert)

Silicon Dioxide (SiO₂)

River Stone (Granitic Gneiss)

Foliated Granitic Gneiss

Quartz (Milky/Cloudy Variety)

Silicon Dioxide (SiO2)

Gneiss (with Quartz and Mica)

Gneiss

Green Schist

Greenschist (composed primarily of Chlorite, Actinolite, and Epidote)

Pyrite

Iron Disulfide (FeS2)

Carnelian

Carnelian (Microcrystalline Quartz, SiO2)

Yellow Quartz (Citrine Quartz or Yellow Chalcedony)

Silicon Dioxide (SiO2)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Gneiss

Gneiss (High-grade metamorphic rock)

Gneiss

Metamorphic rock of high-grade regional metamorphism

Citrine Quartz

Silicon Dioxide (SiO2) with ferric iron impurities

Smoky Quartz

Silicon Dioxide (SiO₂)

Smoky Quartz

Silicon Dioxide (SiO2)

Citrine

Silicon dioxide (SiO2)

Moonstone

Orthoclase Feldspar (KAlSi3O8)

Smoky Quartz

Silicon Dioxide (SiO2)

Smoky Quartz

Silicon Dioxide (SiO2)

Smoky Quartz

Quartz (Silicon Dioxide) - SiO2

Biotite (Black Mica)

K(Mg,Fe)3AlSi3O10(OH,F)2