Conglomerate (River Rock)
Clastic sedimentary rock (primarily SiO2)
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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Travertine
Calcareous Tufa / Travertine (CaCO3)
sedimentary
Terrazzo (with Marble and Granite fragments)
Cementitious or resinous composite containing Calcium Carbonate (CaCO3) and Silicates
sedimentary (man-made composite)
Chert (Flint)
SiO2 (Microcrystalline Quartz)
sedimentary
Asphalt (Bituminous Concrete)
Bituminous mix containing aggregates and petroleum-based binder (CnH2n+2)
not a rock (anthropogenic material/technofossil)
Sandstone (Red Flagstone)
Clastic sedimentary rock (primarily Quartz - SiO2)
sedimentary
Shale or Argillite
Shale (sedimentary) / Argillite (metamorphic)
Sedimentary or Metamorphic (low-grade)
Polished brecciated jasper
Jasper (microcrystalline quartz, SiO₂), likely brecciated and iron-stained
metamorphic
Pyritic Mudstone
Argillaceous rock (FeS2)
sedimentary
Chert / Flint
Silicon Dioxide (SiO2)
sedimentary
Conglomerate
Conglomerate (SiO2, Al2O3, Fe2O3, CaCo3)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Calcite
Calcite (CaCO3)
Mineral
Quartzite River Rock
Quartzite (SiO2)
metamorphic
Mookaite Jasper
Silicified Radiolarite (Silicon Dioxide: SiO2)
sedimentary
Coquina or Fossilized Shell Aggregate
Calcareous bioclastic sedimentary rock (CaCO3)
sedimentary
Quartzite Pebble
Quartzite (SiO2-dominated rock)
metamorphic
Quartzite pebble
Metamorphic rock (mainly SiO2)
metamorphic
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Quartzite (River Cobble)
Metamorphic Quartz-rich Rock
metamorphic
Quartzite
SiO2 (Silicon Dioxide)
metamorphic
Yellow Chert
Microcrystalline Quartz (SiO2)
sedimentary
Weathered sandstone cobble
Quartz-rich sandstone, primarily SiO₂ with clay/iron-oxide cement
sedimentary
Quartzite Cobble
Quartzite (principally SiO2)
metamorphic
Chert (Limonite-stained)
Microcrystalline Quartz (SiO2) with iron oxides
sedimentary
Grey River Pebble (Likely Quartz-rich or Limestone)
Clastic Sedimentary Rock (typically SiO2 or CaCO3 based)
sedimentary
Chert / Jasper
Sedimentary Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Flint / Chalcedony)
Silicon Dioxide (SiO2)
sedimentary
Shale or Argillite
Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)
Sedimentary or Metamorphic (low grade)
Quartzite
Quartzite (SiO2)
metamorphic
Pink Granite
Phaneritic Felsic Igneous Rock (Granite, rich in Potassium Feldspar)
igneous
K2 Jasper (K2 Granite)
Granite with Azurite inclusions (SiO2 + Cu3(CO3)2(OH)2)
igneous
Microcrystalline Quartz (Chert/Agate)
Silicon Dioxide (SiO2)
sedimentary
Pale green tumbled mineral fragment, likely serpentine or green calcite
Probable serpentine-group mineral (Mg3Si2O5(OH)4) or, less likely, calcite (CaCO3); identification is uncertain from the photograph
mineral
Chert (Brecciated or Veined)
Silicon Dioxide (SiO2)
sedimentary
Kimberlite
Kimberlite
igneous
Greywacke Siltstone Pebble / Concretionary River Pebble
Siltstone / Argillite (Fine-grained Sedimentary Rock)
sedimentary
Serpentinite (likely serpentinized ultramafic rock)
Serpentine-group minerals, chiefly antigorite/lizardite; commonly derived from peridotite
metamorphic
Banded Gneiss (River Rock/Pebble)
Gneiss (specifically a banded variety, likely a orthogneiss or paragneiss depending on parent rock)
Metamorphic Rock
Likely petrified wood
Silicified wood, chiefly microcrystalline quartz (SiO₂)
fossil
Granite Cobble
Felsic Intrusive Igneous Rock
igneous
Unakite
Altered Granite (Unakite)
metamorphic