Pyrite
Pyrite (FeS2)
Mineral
Category
Sedimentary Rock (Metamorphosed)
Browse sedimentary rock (metamorphosed) specimens identified by the Rock Identifier community.
Micaceous Rock (likely Muscovite Schist/Gneiss or a Muscovite-rich Specimen)
Predominantly Muscovite (KAl2(AlSi3O10)(F,OH)2), often found in rocks like Muscovite Schist or Muscovite Gneiss.
Metamorphic, Mineral (within a rock type)
Dyed Agate / Painted Stone
Silicon Dioxide (SiO2) with artificial pigment
sedimentary (base), then artificial
Jasper (Milky/Cream Variety)
Silicon Dioxide (SiO2) - variety of Chalcedony
sedimentary (chemical/biological)
River Cobble (Gneiss/Migmatite)
Gneissic Metamorphic Rock (composed mainly of Quartz, Feldspar, and Biotite)
metamorphic
Calcite
Calcite (CaCO₃, Calcium Carbonate)
Mineral
Gneiss (specifically a Granitic Gneiss specimen)
Gneiss (high-grade metamorphic rock primarily composed of Quartz, Feldspar, and Biotite/Amphibole)
metamorphic
Quartz
Silicon Dioxide (SiO2)
Mineral
Zebra Rock (Zebra Stone / Ribbon Stone)
Siltstone with Ferruginous Banding (Primarily Quartz, Kaolinite, and Hematite)
sedimentary
Quartzite with Iron Inclusions
Metamorphosed Quartz Sandstone (SiO2 with Fe2O3)
metamorphic
Marble
Marbles are primarily composed of calcite (calcium carbonate, CaCO3) or dolomite (calcium magnesium carbonate, CaMg(CO3)2).
Metamorphic Rock
Diorite (possibly fine-grained variety or a related intermediate intrusive rock like a felsic gabbro or a dark granodiorite)
Diorite (Igneous rock, intrusive, intermediate composition)
Igneous Rock
River Cobble (likely Basalt or Chert)
Siliceous River Rock / Microcrystalline Quartz / Mafic Igneous
igneous/sedimentary
Quartzite
Quartzite (SiO2)
Metamorphic
Chalcedony (Banded/Mottled Variety)
Chalcedony (a cryptocrystalline variety of Quartz, SiO2)
Mineral
Garnet (Red Garnet)
Garnet Group. The red varieties seen in jewelry are typically Almandine (Fe3Al2(SiO4)3), Pyrope (Mg3Al2(SiO4)3), or a mix of the two (pyrope-almandine series).
Mineral (specifically, a variety of the mineral species Pyrope-Almandine Garnet)
Quartz with Iron Stains
Quartz (SiO2) with iron oxide/hydroxide staining
Mineral
Banded Gneiss
Gneiss (pronounced "nice")
metamorphic
Quartz
SiO₂ (Silicon Dioxide)
Mineral
Herkimer Diamond in Matrix
Quartz (SiO2) in Dolostone (CaMg(CO3)2)
sedimentary (host) / mineral (crystals)
Agate
Agate (a variety of Chalcedony, SiO2)
Mineral
Quartz
Quartz (SiO2, Silicon Dioxide)
Mineral
Ocean Jasper
Silicon Dioxide (SiO2) with various inclusions
igneous/sedimentary mixed (Orbicular Jasper)
Jasper
Silicon Dioxide (SiO2)
Mineral
Bivalve Shell (Fossil or Contemporary)
Class Bivalvie (various genera and species of clams, cockles, etc.)
Sedimentary (Biogenic sediment or biological remain)
Limonite (Iron Ore)
Hydrous Iron Oxide (goethite, lepidocrocite)
Mineral
Note: Image shows a biological specimen (Rat), not a rock. Representative geological equivalent: Galena (due to lead-grey colors in fur).
Galena (PbS)
mineral
Kyanite
Kyanite (Al2SiO5)
Mineral
Quartz
Quartz (Silicon Dioxide, SiO2)
Mineral
Quartz
Silicon dioxide (SiO₂)
Mineral
River Stone (likely Basalt or Chert)
Silicon Dioxide (SiO2) for chert or Mafic Extrusive Rock for basalt
igneous/sedimentary
Quartz (likely macrocrystalline variety)
Quartz (SiO₂)
Mineral
Lapis Lazuli (blue bead) and Moss Agate (green heart)
Lapis Lazuli (lazurite-based rock) and Moss Agate (SiO2 with manganese/iron inclusions)
metamorphic (Lapis) and sedimentary/igneous assoc. (Moss Agate)
Banded Gneiss
Gneiss (variable mineral composition)
metamorphic
Blue Quartz
Quartz (SiO2) with inclusions
Mineral
Quartz
Silicon Dioxide (SiO2)
Mineral
Orthoclase Feldspar (or K-Feldspar)
Orthoclase (KAlSi3O8)
Mineral
Chert or Flint (polished/water-worn)
Chert (a microcrystalline or cryptocrystalline variety of quartz, SiO2). Flint is a specific variety of chert.
Sedimentary (most likely, as Chert is a sedimentary rock often found as nodules in limestone or as bedded deposits; however, it can also form by metasomatic replacement, which leans towards metamorphic processes under certain conditions)
Schist
Schist (various mineralogical compositions including mica, chlorite, talc, etc.)
Metamorphic
Jasper (likely Lake Superior Jasper)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary (silica-rich mineral variety)
Quartz
Quartz (SiO₂)
Mineral
Smoky Quartz
SiO2 (Silicon Dioxide)
Mineral