Anthracite Coal
Anthracite (Carbon-rich metamorphic sedimentary rock)
Category
Browse mineral on sedimentary rock specimens identified by the Rock Identifier community.
Anthracite Coal
Anthracite (Carbon-rich metamorphic sedimentary rock)
River Pebble (Quartzite/Siltstone mixture)
Silicon Dioxide (SiO2) mixture with varied clastic minerals
Orange Calcite
Calcite (Calcium Carbonate, CaCO3)
Halite
Halite (NaCl)
Pyrite on Quartz
Iron Sulfide (FeS2) on Silicon Dioxide (SiO2)
Quartz (possibly milky quartz)
Quartz (Silica; SiO₂)
Coal
Bituminous or Anthracite coal (carbon-rich sedimentary rock)
Granite
Plutonic felsic rock (Quartz, Feldspar, Mica)
Fossiliferous Brachiopod in Shale
Brachiopoda (Phylum) preserved in Carbonaceous Shale
Ironstone Concretion (likely)
Goethite/Hematite/Limonite cemented sediment
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert Nodule (Flint)
Chert (Cryptocrystalline Silica - SiO2)
Jasper (Chocolate or Brown Jasper)
Silicon Dioxide (SiO2)
Travertine
Travertine (CaCO3 - Calcium Carbonate)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Granite (Specimen: Logan Rock)
Phaneritic plutonic igneous rock (mainly Quartz, Feldspar, and Mica)
Red Jasper (beads)
SiO₂ (Silicon Dioxide)
Banded Iron Formation (BIF) with Quartz
Banded Iron Formation, often composed of alternating layers of hematite (Fe2O3) or magnetite (Fe3O4) and chert (microcrystalline quartz, SiO2)
Sandstone (Ferruginous)
Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 staining)
Carnelian (Chalcedony variety)
SiO2 (Silicon Dioxide)
Sandstone
Arenite or Sandstone
Rough Agate/Chert Nodules
Cryptocrystalline Quartz (SiO2)
Granite
Phaneritic Plutonic Igneous Rock (primarily composed of quartz, alkali feldspar, and plagioclase)
Limestone
Calcium Carbonate (CaCO3)
Schist
Mica Schist (primarily consisting of muscovite KAl2(AlSi3O10)(OH)2 or biotite K(Mg,Fe)3(AlSi3O10)(OH)2)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Extrusive volcanic rock)
Basalt Porphyry
Porphyritic Basalt
Quartz
Silicon Dioxide (SiO2)
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
Chert (Yellow Jasper)
Microcrystalline Quartz (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Quartz
Silicon dioxide (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Travertine (used in construction, not a 'specimen' in situ)
Travertine
Chert (Common Opal variant)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Jasper
Jasper (Silicon Dioxide, SiO2)
Halite (Rock Salt)
Halite; NaCl (Sodium Chloride)
Quartzite River Rock
Quartzite (primarily SiO2)
Amethyst
Amethyst (Silicon Dioxide - SiO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)