Agate (specifically a Blue Agate Geode Slice)
Chalcedony (cryptocrystalline variety of Quartz); SiO2
Category
Browse igneous or sedimentary (anthropogenic modification) specimens identified by the Rock Identifier community.
Agate (specifically a Blue Agate Geode Slice)
Chalcedony (cryptocrystalline variety of Quartz); SiO2
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
Amethyst and Hematite Bracelet
Amethyst (SiO2) and Hematite (Fe2O3)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Pyrite
Iron Sulfide (FeS2)
Unidentified Rock Fragment
Unknown
Gneiss
Gneissic Metamorphic Rock
Rough Quartz (or Quartzite pebble)
Silicon Dioxide (SiO2)
Gneiss (Metamorphic Cobble)
Gneiss (High-grade Regional Metamorphic Rock)
Greenschist
Greenschist facies rock (containing chlorite, actinolite, albite, and epidote)
Hematite (Iron Ore)
Hematite (Fe2O3)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Pyrite
Iron Disulfide (FeS2)
Hematite
Iron(III) oxide (Fe2O3)
Green Calcite
Calcium Carbonate (CaCO3)
Gneiss
Gneiss (high-grade metamorphic rock typically composed of quartz, feldspar, and mica)
Quartz Pebble
Silicon Dioxide (SiO2)
Yellow Quartz Pebble (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
Yellow Agate
Chalcedony (cryptocrystalline Quartz), SiO2
Blue Calcite
Calcium Carbonate (CaCO3)
Gneiss
Gneiss
Granite Gneiss
High-grade regional metamorphic rock (Quartz-Feldspar Gneiss)
Agate Geode
Cryptocrystalline Quartz (SiO2)
Pyrite (Iron Pyrite)
Iron Sulfide (FeS2)
Quartz Crystal (specifically a small Clear Quartz point)
Silicon Dioxide (SiO2)
Chalcedony (Agate)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Carnelian
Carnelian Agate (Silica: SiO2)
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Gneiss (Granitic Gneiss)
Gneiss (from German Gneis, related to 'spark')
Fluorite
Calcium Fluoride (CaF2)
Milky Quartz
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Quartz (Smoky/Milky variety)
Silicon Dioxide (SiO2)
Pyrite
Iron Disulfide (FeS2)
Fluorite (Rainbow Fluorite Point)
Calcium Fluoride (CaF2)
Hematite
Iron(III) oxide (Fe2O3)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Mica Schist (with Golden/Biotite inclusions)
K(Mg,Fe)3AlSi3O10(F,OH)2 (Biotite), KAl2(AlSi3O10)(F,OH)2 (Muscovite)
Quartz
SiO₂ (Silicon Dioxide)
Red Jasper
Silicon Dioxide (SiO2) - variety of Chalcedony
Labradorite (tumbled)
Labradorite (a plagioclase feldspar mineral between anorthite and albite; chemical formula: (Ca,Na)(Si,Al)4O8)
Clear Quartz (or Rock Crystal)
Quartz (SiO₂ - Silicon Dioxide)