Conglomerate (River Rock Aggregate)
Conglomerate (Lithic-clast conglomerate)
sedimentary
Category
Mineral Based Alloy (Anthropogenic)
Browse mineral based alloy (anthropogenic) specimens identified by the Rock Identifier community.
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Chert (variations include Chalcedony and Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
River Siltstone / Mudstone Pebble
Siltstone (composed of mixed silicate and carbonate minerals)
sedimentary
Diorite
Intermediate Phaneritic Igneous Rock (Diorite)
igneous
Granodiorite Pebble
Granodiorite
igneous
Granite
Phaneritic Plutonic Rock (High Silica content)
igneous
Shale
Clastic sedimentary rock (primarily clay and silt minerals)
sedimentary
Granite
Felsic Intrusive Igneous Rock
igneous
Porphyritic Amygdaloidal Basalt
Amygdaloidal Porphyritic Basalt (Mafic volcanic rock)
igneous
River Cobble (likely Basalt or Rhyolite)
Extrusive Igneous Rock (Mafic or Intermediate)
igneous
Sandstone
Arenite (Siliclastic sedimentary rock, primarily SiO2)
sedimentary
Ferruginous Breccia
Breccia with Iron-rich (Hematite/Goethite) Matrix
sedimentary
Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Muscovite Mica
Muscovite (Potassium Mica) KAl2(AlSi3O10)(OH)2
Mineral
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Toast
Triticum aestivum (processed)
not a geological specimen
Granite
Granite (Phaneritic Igneous Rock)
igneous
Vesicular Basalt (or Scoraceous Basalt)
Basalt (Vesicular texture)
igneous
Granite (specifically Rapakivi Granite)
Phaneritic Felsic Igneous Rock (Granite)
igneous
Chert (specifically Banded Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Sandstone
Arenite (SiO2 principal)
sedimentary
Mica Schist
Mica Schist (primarily Muscovite and/or Biotite composition)
metamorphic
Basalt
Mafic Igneous Rock (composed primarily of pyroxene and calcium-rich plagioclase)
igneous
Vesicular Basalt
Extrusive mafic igneous rock; primarily (Ca,Na)(Mg,Fe,Al,Si)2O6 (Pyroxene) and (Ca,Na)Al(Al,Si)Si2O8 (Plagioclase Feldspar)
igneous
Granite
Phaneritic Plutonic Rock (Granite)
igneous
Fluorite
Fluorite (Calcium Fluoride, CaF2)
mineral
Basalt with Quartz Veining
Veined Basalt (composed primarily of plagioclase feldspar, pyroxene, and olivine with quartz/calcite infill)
igneous
Diorite
Intrusive Igneous Rock (Intermediate Composition)
igneous
Biotite Schist
Biotite Schist
metamorphic
Ironstone Concretion
Ironstone (primarily Siderite or Limonite / Goethite, FeO(OH)·nH2O)
sedimentary
Basalt
Basalt
igneous
Gabbro
Gabbro (mafic intrusive rock)
igneous
Basalt with Quartz/Calcite Veins
Amygdaloidal Basalt (SiO2 or CaCO3 inclusions)
igneous
Chert (specifically Tan Chert)
Chert (SiO2)
sedimentary
Sandstone (Iron-stained)
Arenite (composed primarily of SiO2 with Fe2O3 staining)
sedimentary
Granodiorite
Granodiorite (phaneritic intrusive igneous rock)
igneous
Granite (specifically Pink Granite)
Phaneritic Plutonic Rock (High Potassium Feldspar Granite)
igneous
Diorite (Salt and Pepper Rock)
Diorite
igneous
Pink Granite
Granite (Phaneritic intrusive rock rich in K-feldspar)
igneous
Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Sandstone
Arenite (predominantly SiO2 quartz grains)
sedimentary
Brecciated Chert
Brecciated Chert (Microcrystalline Quartz, SiO2)
sedimentary