Porphyritic Basalt
Porphyritic Basalt with Plagioclase Phenocrysts
igneous
Category
Not A Rock
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Geode
Quartz nodule / Chalcedony-lined cavity
sedimentary
Sandstone
Arenite (SiO2, often with CaCO3 or Fe2O3 cement)
sedimentary
Serpentine
Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
metamorphic
Serpentine
Antigorite, Lizardite, or Chrysotile (Mg3Si2O5(OH)4)
metamorphic
Sandstone
Arenite (SiO2 dominant)
sedimentary
Granitic rock, likely weathered granite
Granite; primarily quartz, feldspar, and mica
igneous
Quartzite Pebble with Feldspar Vein
Quartzite (SiO2) with Feldspar (KAlSi3O8)
metamorphic
Schist (likely Mica Schist)
Mica Schist
metamorphic
Yellow Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Beach Pebble (Basalt/Porphyry)
Weathered Basalt or Porphyry
igneous
Quartz pebble with calcite
Silicon dioxide (SiO2) with Calcium carbonate (CaCO3)
sedimentary
Yellow Jasper with Hematite
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
sedimentary
Veined Limestone (Micrite) with Quartz/Calcite Veins
Calcium Carbonate (CaCO3) with Silicate or Carbonate inclusions
sedimentary
Mixed Rock Collection (Pebbles and Stones)
Various geological specimens
igneous, sedimentary, and metamorphic
Weathered, rounded rock (likely metamorphic or igneous)
Undetermined; possibly a quartz- and feldspar-bearing rock
metamorphic
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Greenstone, likely altered basalt
Metabasalt (chlorite–actinolite–epidote assemblage), likely greenschist-facies greenstone
metamorphic
Serpentine-rich serpentinite
Serpentinite, chiefly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), with possible magnetite, brucite, and carbonate
metamorphic
Sandstone with Lichen and Iron Oxide Staining
Quartz Arenite / Sandstone
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Druzy Quartz on Limestone
Silicon Dioxide (SiO2) on Calcium Carbonate (CaCO3)
sedimentary
Xenolith in Basalt
Mafic Igneous Rock with Felsic Inclusion
igneous
Gray granite or granitic gneiss fragment
Granite; mainly quartz, feldspar, and mica (exact identification is uncertain from the image)
igneous
Weathered granite or granitic gneiss
Granite; predominantly quartz, feldspar, and mica (exact identification is uncertain from the image)
igneous
Ruby in Zoisite
Anyolite (composite of Corundum and Zoisite)
metamorphic
Granite
Phaneritic plutonic rock (primarily Quartz, Feldspar, and Mica)
igneous
Granite
Intrusive Igneous Rock (composed mainly of quartz, alkali feldspar, and plagioclase)
igneous
Granite
Intrusive Igneous Rock
igneous
Granite
Felsic intrusive igneous rock
igneous
Shale
Shale (Lutite)
sedimentary
Vesicular Basalt (Pumice-like)
Vesicular Basalt
igneous
Granodiorite
Granodiorite (containing Plagioclase, Quartz, and Biotite)
igneous
Serpentine
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
metamorphic
Pink Granite
Phaneritic Felsic Intrusive Igneous Rock
igneous
Granite
Intrusive Igneous Rock (composed primarily of quartz, alkali feldspar, and plagioclase)
igneous
Basalt
Extrusive Igneous Rock
igneous
Unknown Rock Fragment
Unknown
unknown
Fossil Snail
Gastropoda fossil
fossil
Desert Rose (Baryte or Selenite variant)
Barium Sulfate (BaSO4) or Gypsum (CaSO4·2H2O) with Sand inclusions
mineral
Granite
Intrusive Igneous Rock
igneous
Granite boulder
Granite, chiefly quartz–feldspar–mica plutonic rock
igneous