Chert with Fossil Brachiopod
Microcrystalline Quartz (SiO2) with Calcitic Brachiopod inclusion
sedimentary
Category
Synthetic Material (Not A Rock Or Mineral)
Browse synthetic material (not a rock or mineral) specimens identified by the Rock Identifier community.
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River Pebble (Quartz-rich)
Silicon Dioxide (SiO2) with various inclusions
sedimentary
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Tumbled porphyritic granite
Granite, primarily quartz, alkali feldspar, plagioclase, and biotite/hornblende
igneous
Basalt
Extrusive Mafic Igneous Rock (composed primarily of plagioclase feldspar and pyroxene)
igneous
Quartzite River Rock
Quartzite (primarily SiO2)
metamorphic
Turquoise
Hydrated phosphate of copper and aluminium - CuAl6(PO4)4(OH)8·4H2O
mineral
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Petrified Wood
Silicified Wood (primarily Quartz / Chalcedony: SiO2)
metamorphic
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Fossiliferous Limestone
Fossiliferous Calclutite / Bio-calcarenite (CaCO3)
sedimentary
Vesicular Rhyolite
Rhyolite (High-silica volcanic rock)
igneous
Yellow Jasper
Silicon Dioxide with iron inclusions (SiO2)
sedimentary
Weathered porphyritic volcanic rock
Likely altered andesite or rhyolite porphyry
igneous
Porphyry
Porphyritic Igneous Rock
igneous
Siltstone or Mudstone
Argillaceous sedimentary rock
sedimentary
Granite
Granite (Felsic Plutonic Rock)
igneous
Serpentinite with carbonate veins
Serpentinite; chiefly serpentine-group minerals (antigorite/lizardite, Mg₃Si₂O₅(OH)₄) with white calcite or magnesite veins
metamorphic
Limonite/goethite-rich ironstone (probable)
Limonite, chiefly hydrated iron oxides; commonly goethite, α-FeO(OH), with possible quartz or host-rock inclusions
mineral
Quartz-bearing iron-rich rock, possibly quartzite or hydrothermal breccia
Quartz (SiO₂) with iron oxides/hydroxides, likely limonite/goethite; exact host rock is uncertain from the photograph
metamorphic
Ironstone with Pyrite
Ferruginous Sandstone (Fe2O3) with minor Sulfide minerals (FeS2)
sedimentary
Blue Sphalerite (likely dyed or treated Druzy Quartz/Agate)
Zinc Sulfide (ZnS) or Silicon Dioxide (SiO2) with trade-name enhancement
Mineral
Granite
Granite (Phaneritic intrusive igneous rock) - Composition: SiO2, Al2O3, K2O, Na2O
igneous
Scoria
Extrusive Basaltic Scoria
igneous
Weathered sandstone or siltstone
Clastic sedimentary rock, chiefly quartz and feldspar grains cemented by clay, silica, or iron oxides
sedimentary
Chert Nodule / Flint
Microcrystalline Quartz (SiO2)
sedimentary
Serpentine
Serpentinite (group of minerals based on (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4)
metamorphic
Bivalve Fossil (Internal Mold)
Bivalvia (Phalladomya or similar genus)
fossil
Serpentinite
Serpentinite (composed primarily of minerals in the serpentine group: (Mg,Fe)3Si2O5(OH)4)
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Granite
Granite (Mainly Quartz, Alkali Feldspar, and Plagioclase)
igneous
Quartzite Pebbles
Meta-quartzite (SiO2)
metamorphic
Basalt
Basalt
igneous
Snowflake Obsidian
Volcanic Glass with Spherulite inclusions (Amorphous SiO2 + Cristobalite)
igneous
Chert (Jasper)
Silicon Dioxide (SiO2)
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Garden Pebble (Quartzite or Limestone fragment)
Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3) fragment
sedimentary
Chert (Jasper/Chalcedony variety)
Microcrystalline Quartz (SiO2)
sedimentary
Blue Apatite
Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)
mineral
Petrified Wood
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
fossil
Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Granite
Granite (a felsic intrusive igneous rock)
igneous