Shale
Mudstone (composed primarily of clay minerals like kaolinite, illite, and smectite, with quartz and calcite)
Category
Browse sedimentary (fossilized organic remain) specimens identified by the Rock Identifier community.
Shale
Mudstone (composed primarily of clay minerals like kaolinite, illite, and smectite, with quartz and calcite)
Porphyry
Porphyritic Igneous Rock
Porphyry
Porphyritic igneous rock
Porphyritic Diabase (Porphyry)
Porphyritic Diabase / Microgabbro
Porphyritic Basalt
Basalt (porphyritic texture)
Basalt with Granite Inclusions (Xenolith)
Mafic Igneous Rock (Basalt) with Felsic Igneous Inclusion (Granite)
Porphyry
Porphyritic Basalt or Andesite
Porphyry
Porphyritic Basalt/Andesite
Chert (often called Flint or Jasper)
Microcrystalline quartz (SiO2)
Chert
Sedimentary Cryptocrystalline Quartz (SiO2)
Chert (specifically Cryptocrystalline Quartz)
Silicon dioxide (SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline silica (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (White/Gray variety)
Silicon Dioxide (SiO2 / Cryptocrystalline Quartz)
Chert (Flint)
Chert (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Jasper)
Cryptocrystalline Silicon Dioxide (SiO2)
Fossil shell fragment (likely brachiopod or bivalve)
Indeterminate fossilized carbonate shell; likely Brachiopoda or Bivalvia
Fossiliferous Limestone
Bioclastic Limestone (composition: CaCO3)
Fossil-bearing Sedimentary Rock
Sedimentum cum fossili
Fossilized Crinoid Stem
Crinoidea (Echinodermata)
Mother of Pearl (Nacre) / Shell Fragment
Biogenic Calcium Carbonate (Aragonite and Conchiolin)
Fossiliferous Limestone
Biogenic Sedimentary Rock
Chert (Yellow Jasper/Honey Chert)
Silicon Dioxide (SiO2)
Fossilized Oyster Shell
Ostrea / Exogyra (Phylum Mollusca)
Petoskey Stone
Hexagonaria percarinata
Coal (likely Bituminous or Lignite)
Organic Sedimentary Rock (Carbonaceous)
Fossilized Shark Tooth (Dermal Denticle or worn tooth fragment)
Elasmobranchii (fossil remains)
Chert (White Chert)
Silicon Dioxide (SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Flint (Chert Node)
Silicon Dioxide (SiO2)
Chert (and Chalcedony)
Microcrystalline Quartz (SiO2)
Quartzite
Quartzite (primarily SiO2)
Quartzite
Quartzite (SiO2)
Pyrite
Iron Sulfide (FeS2)
Fossilized Coral (Petoskey Stone type)
Hexagonaria percarinata (Fossilized Rugose Coral)
Chert with Quartz Veins
Microcrystalline silica (SiO2)
Banded Agate
Cryptocrystalline variety of Quartz (SiO2)
Dendritic Agate
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Amygdaloidal Basalt with Quartz/Zeolite Infill
Amygdaloidal Basalt (extrusive volcanic rock with SiO2 or CaAl2Si3O10·3H2O infill)