Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Category
Sedimentary Rock (Specifically A Concretion Or Possibly A Geode)
Browse sedimentary rock (specifically a concretion or possibly a geode) specimens identified by the Rock Identifier community.
Ocean Jasper
Orbicular Jasper/Microcrystalline Quartz (SiO2)
sedimentary
Quartz (Milky or Common Quartz)
Silicon Dioxide (SiO2)
mineral
Chert / Flint (with quartz or calcite inclusion)
Silicon dioxide (SiO2)
sedimentary
Asphalt (Road Aggregate)
Asphalt concrete / Bituminous mixture
anthropogenic sedimentary (technolith)
Basalt
Vesicular Basalt
igneous
Pink Granite
Phaneritic intrusive igneous rock (Felsic)
igneous
Carnelian
Carnelian (SiO2 - Silicon Dioxide with Hematite impurities)
mineral
Amethyst
Amethyst (Silicon Dioxide with Iron impurities, SiO2)
mineral
Limestone (specifically a Crushed Aggregate fragment)
Calcium Carbonate (CaCO3)
sedimentary
Yellow Chalcedony (Agate)
Silicon Dioxide (SiO2)
mineral
Quartz Geode (with Calcite influence)
Silicon Dioxide (SiO2) with possible Calcium Carbonate (CaCO3)
mineral
Botryoidal Chalcedony
Silicon Dioxide (SiO2)
mineral
Amethyst (Pale/Lavender variety)
Silicon Dioxide (SiO2)
mineral
Crushed Stone (Gravel/Aggregates)
Crushed rock aggregate (varied composition including Granite, Limestone, and Quartz)
sedimentary and igneous (mixed)
Shale (Beach-worn)
Laminated Pelite (primarily clay minerals and quartz)
sedimentary
Yellow Agate
Agate (Varietal form of Chalcedony/Quartz, SiO2)
mineral
Gneiss with Quartz Veining
Gneiss (High-grade regional metamorphic rock)
metamorphic
Fossil Shark Tooth (Otodus obliquus)
Otodus obliquus; hydroxyapatite (mineralized form Ca5(PO4)3(OH))
sedimentary (fossiliferous)
Pink Granite
Granite (Phaneritic Felsic Igneous Rock)
igneous
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
sedimentary
Spinosaurus Tooth
Spinosaurus aegyptiacus (fossilized in Hydroxyapatite)
sedimentary
White Marble
Calcite-rich Metasomatized Carbonate (CaCO3)
metamorphic
Yellow Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
mineral
Granite (specifically Pink or Alkali Feldspar Granite)
Felsic Plutonic Rock (primarily SiO2 with KAlSi3O8)
igneous
Shale
Fissile Mudstone (primarily composed of phyllosilicate minerals like kaolinite, montmorillonite, and illite)
sedimentary
Carnelian (Chalcedony variety)
SiO2 (Silicon Dioxide)
Mineral
Limonite after Pyrite (Prophecy Stone)
Limonite (FeO(OH)·nH2O) replacing Pyrite (FeS2)
Mineral pseudomorph
Quartz (Milky or Cloudy Quartz)
Silicon Dioxide (SiO2)
mineral
Milky Quartz (Common Quartz)
Quartz (Silicon Dioxide, SiO2)
mineral
Moqui Marble (Shaman Stone)
Ironstone Concretion (Fe2O3 - Hematite/Goethite shell with Sandstone core)
sedimentary
Red Jasper
Jasper (Silicon Dioxide, SiO2)
mineral
Yellow Jasper
Silicon Dioxide (SiO2) - Opaque variety of Chalcedony/Quartz
sedimentary
Pumice or Scoria
Vesicular volcanic rock
Igneous
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Thunderegg (Agetized Geode nodule)
Rhyolitic Agate Nodule (SiO2 filling volcanic cavities)
igneous
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
mineral
Ocean Jasper (Orbicular Jasper)
Silicon Dioxide (SiO2)
Sedimentary Rock
Concrete / Anthropogenic Conglomerate
Man-made composite material (Portland cement, aggregate, and water)
not a natural rock
Rough Quartz in Pegmatite Matrix
Quartz (Silicon Dioxide - SiO2) in Granitic Pegmatite
igneous
Marble
Marbles are primarily composed of calcite (calcium carbonate, CaCO3) or dolomite (calcium magnesium carbonate, CaMg(CO3)2).
Metamorphic Rock
Amethyst (Chevron or Banded Amethyst)
Silicon Dioxide (SiO2) with iron impurities
mineral