Granitic Gneiss
Gneiss (containing Potassium Feldspar and Quartz)
Category
Browse sedimentary rock (possibly composed of various minerals) specimens identified by the Rock Identifier community.
Granitic Gneiss
Gneiss (containing Potassium Feldspar and Quartz)
Concretion (Sandstone)
Carbonate-cemented Sandstone Concretion
Magnetite (likely with weathered Limonite/Hematite)
Magnetite (Fe3O4) with iron oxide weathering
Ocean Jasper (Orbicular Jasper)
Silicon Dioxide (SiO2) with inclusions
Travertine (Ceramic Tile)
Terrestrial Sedimentary Rock / Calcium Carbonate (CaCO3)
Veined Quartz
SiO2 (Silicon Dioxide)
Chert (varietal Flint)
Silicon Dioxide (SiO2)
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
Sulfur (with possible Cullet Glass or Slag imitation)
Native Sulfur (S8)
Quartz (Milky or Common Quartz)
Silicon Dioxide (SiO2)
Quartz (Common or Milky Quartz)
Silicon Dioxide (SiO2)
Fossilized Shark Tooth
Carcharodon carcharias (fossilized) / Hydroxyapatite permineralized with silica or iron
Basalt with Secondary Mineralization (Likely Zeolites or Calcite)
Aphanitic mafic volcanic rock with secondary mineral inclusions (e.g., CaAl2Si3O10·3H2O for Scolecite)
Banded Agate
Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified wood (Quartz, SiO2)
Diorite (Salt and Pepper Rock)
Diorite
Red Jasper (River-worn Pebble)
Silicon Dioxide (SiO2) with Ferric Iron inclusions
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Fluorite
Calcium Fluoride (CaF2)
Sandstone
Arenite (primarily SiO2)
Garnet (Almandine)
Almandine, Fe3Al2(SiO4)3
Basalt with Iron Oxidation
Mafic Igneous Rock (Basalt)
Rhodochrosite
Manganese Carbonate (MnCO3)
Milky Quartz
Silicon Dioxide (SiO2)
Sandstone Chert Concretion
Silica-cemented Concretion (primarily SiO2)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Sandstone
Arenite (primarily SiO2)
Magnetite / Ironstone
Magnetite (Fe3O4)
Porphyritic Basalt (Amygdaloidal)
Porphyritic Mafic Volcanic Rock (Amygdaloidal Basalt)
Blue Lace Agate
Chalcedony (cryptocrystalline variety of Quartz), SiO2
Clear Quartz
Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Copper Ore with Chrysocolla and Azurite
Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Chrysocolla) / Cu3(CO3)2(OH)2 (Azurite)
Sandstone (with ripple marks)
Arenite / Quartz Sandstone
Dalmatian Stone
Peralkaline Quartz-Feldspar Porphyry with Arfvedsonite
Basalt with Plagioclase Phenocrysts
Porphyritic Basalt (primarily SiO2, MgO, FeO, and CaO)
Porphyritic Basalt
Amygdaloidal Porphyritic Basalt
Porphyritic Andesite
Andesite
Sandstone (likely Quartzose Sandstone)
Arenite
Blue Apatite
Apatite (Group), Ca5(PO4)3(F,Cl,OH)
Sandstone Concretion
Septarian or Carbonate-cemented Sandstone Concretion
Banded Agate
Silicon Dioxide (SiO2) - Chalcedony variety