Agate (Chalcedony)
Cryptocrystalline Quartz (SiO2)
mineral
Category
Mineralogical Specimen
Browse mineralogical specimen specimens identified by the Rock Identifier community.
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Horn Coral Fossil
Rugosa (extinct order of solitary corals)
sedimentary
Granite Pebble
Granite (Phaneritic intrusive igneous rock)
igneous
Black Tourmaline
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)
mineral
Fossiliferous Limestone
Fossiliferous Calcilutite / Biomicrite
sedimentary
Concrete / Anthropogenic Conglomerate
Man-made composite material (Portland cement, aggregate, and water)
not a natural rock
Granite (with Muscovite Mica)
Phaneritic Felsic Igneous Rock (primarily Quartz SiO2, K-Feldspar KAlSi3O8, and Muscovite KAl2(AlSi3O10)(OH)2)
igneous
Granite Pegmatite with Tourmaline and Muscovite
Pegmatite (Feldspar: KAlSi3O8, Quartz: SiO2, Schorl: NaFe2+3Al6(Si6O18)(BO3)3(OH)3(OH))
igneous
Dyed Agate
SiO2
Mineral
Vesicular Basalt River Cobble
Vesicular Basalt
igneous
Sandstone (Ferruginous)
Arenite (Fe-rich SiO2)
sedimentary
Botryoidal Chalcedony (likely Desert Rose/Agatized Geode Crust)
Silicon Dioxide (SiO2)
mineral
Jasper (Red Jasper with Quartz veins)
Jasper (Silicon Dioxide, SiO2)
sedimentary
Vuggy Quartz / Chert
Silicon Dioxide (SiO2)
sedimentary
Banded Chert (Ironstone/Jasper)
Cryptocrystalline Quartz (SiO2) with Iron Oxides
sedimentary
Porphyritic Basalt
Basalt with Feldspar Phenocrysts
igneous
Chert (and Chalcedony)
Silicon Dioxide (SiO2)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Granite featuring Quartz Vein
Phaneritic Felsic Igneous Rock (Quartz, Orthoclase Feldspar, Mica)
igneous
Chert (Jasper-bearing)
Chert (Silicon Dioxide, SiO2)
sedimentary
Yellow Chalcedony or River Jasper
Silicon Dioxide (SiO2)
sedimentary
Chert (Jasper/Agate variety)
Cryptocrystalline Quartz (SiO2)
sedimentary
Shale with Plant Fossils / Carbonaceous Shale
Laminated Mudrock (Siliciclastic)
sedimentary
Pink Polished Marble (or Limestone) Pillar
Recrystallized Calcium Carbonate (CaCO3)
metamorphic
Iron-stained Quartz
Silicon Dioxide with Iron Oxide (SiO2 with Limonite/Hematite impurities)
mineral
Fossil Sand Dollar (Echinoidea)
Phylum Echinodermata, Class Echinoidea (likely Dendraster or Scutella)
sedimentary
Gold in Quartz Matrix
Native Gold (Au) with Quartz (SiO2) and Slate/Shale
mineral
Chert (Chalcedony/Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Quartz Geode (River Cobble)
Silicon Dioxide (SiO2)
mineral
Carnelian
SiO2 (Chalcedony with iron oxide impurities)
mineral
Chert (Chert / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Granitic Pegmatite with Biotite
Pegmatitic Granite (contains KAlSi3O8, SiO2, K(Mg,Fe)3AlSi3O10(OH)2)
igneous
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with Bioclastic Inclusions
sedimentary
Rough Quartz (Iron-stained)
Silicon Dioxide (SiO2)
mineral
Chert (Jasper variation)
Silicon Dioxide (SiO2)
sedimentary
Chalcedony (Common Opal or Agate)
Silicon Dioxide (SiO2)
mineral
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Chalcedony Nodule (Commonly known as Agate or Chert)
Microcrystalline Quartz (SiO2)
mineral
Alkali Basalt with iron oxidation
Mafic Volcanic Rock (Fe-bearing Basalt)
igneous
Basalt with Vesicular Texture (Beach Cobble)
Vesicular Basalt (Aphanitic Igneous Rock)
igneous
Sandstone (Micaceous)
Arenite (composed primarily of SiO2)
sedimentary
Granite (Pink/Potassium-rich)
Phaneritic Plutonic Felsic Igneous Rock (primarily SiO2 with KAlSi3O8)
igneous