Limestone
Calcium Carbonate (CaCO3)
sedimentary
Category
Sedimentary Or Metamorphic (Base Substrate)
Browse sedimentary or metamorphic (base substrate) specimens identified by the Rock Identifier community.
Learn about Sedimentary Or Metamorphic (Base Substrate) in the encyclopedia
View all →
Chert
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Aquamarine
Beryl (Be3Al2Si6O18)
Mineral
Blue Kyanite
Kyanite (Al2SiO5)
metamorphic
Dark mafic rock, likely basalt
Basalt (fine-grained assemblage chiefly plagioclase and pyroxene, commonly with olivine and iron oxides)
igneous
Greenschist
Greenschist facies metamorphic rock
metamorphic
Ferruginous Conglomerate (or Iron-Rich Concrete/Slag)
Clastic Sedimentary (Silicon Dioxide/Iron Oxide matrix)
sedimentary
Schist (containing Muscovite Mica and Chlorite)
Mica Schist
metamorphic
Glauconite
Glauconite (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2
mineral
Chalcedony (Agate/Jasper mix)
Cryptocrystalline Sillimanite (Quartz) - SiO2
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Argillite (with Barnacles)
Argillite (metamorphosed mudstone/shale)
metamorphic
Tiger's Iron
Pseudomorphic Quartz Aggregate (contains SiO2 with Fe2O3 and FeOOH)
metamorphic
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Dark gray metamorphic rock, likely hornfels or fine-grained amphibolite
Hornfels/amphibolite; commonly quartz, feldspar, amphibole, biotite, and minor sulfides
metamorphic
Banded Slate Pebble
Metamorphosed Mudstone / Slate
metamorphic
Green Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Bumblebee Jasper
Fossiliferous Calcite containing Orpiment and Realgar
sedimentary
Gneiss
Metamorphic Gneiss (High-grade regional metamorphism)
metamorphic
Gneiss
Metamorphic Gneiss (High-grade regional metamorphism)
metamorphic
Magnetite
Magnetite (Iron(II,III) oxide, Fe3O4)
mineral
Garnet
Almandine (Fe3Al2(SiO4)3)
mineral
Magnetite (Iron Ore)
Magnetite (Fe3O4)
mineral
Magnetite
Fe3O4 (Iron(II,III) oxide)
mineral
Quartz
Quartz (SiO2 - Silicon Dioxide)
Mineral
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Dendritic Opal (Common Opal)
Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
mineral
Banded Agate (specifically Moss Agate or Plume Agate variety)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
mineral
Kyanite in Quartz
Kyanite (Al2SiO5) with Quartz (SiO2) matrix
metamorphic
Likely purple quartzite or purple chert
Quartzite/chert, predominantly microcrystalline SiO₂; exact identification requires testing
metamorphic
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Gneiss
Gneiss (Metamorphic Rock)
metamorphic
Gneiss
Gneissic Metamorphic Rock
metamorphic
Gneiss
Gneissic Metamorphic Rock
metamorphic
Coquina
Biogenic Limestone (Coquina)
sedimentary
Coquina
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Coquina
Biogenic Limestone (Coquina)
sedimentary
Chert (River Pebble)
Chert (Microcrystalline Silicon Dioxide, SiO2)
sedimentary
Chert (Nodule)
Chert (mainly Microcrystalline or Cryptocrystalline Quartz, SiO2)
sedimentary
Fossiliferous Limestone (Coquina)
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Coquina
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Chert (specifically Flint or Gray Chert)
Silicon Dioxide (Microcrystalline Quartz), SiO2
sedimentary