Rock Identifier

Category

Sedimentary Rock (Technically Chert, A Microcrystalline Quartz)

Browse sedimentary rock (technically chert, a microcrystalline quartz) specimens identified by the Rock Identifier community.

Coquina (Bioclastic Limestone (composed primarily of CaCO3)) — sedimentary

Coquina

Bioclastic Limestone (composed primarily of CaCO3)

Gneiss Pebble (Gneiss) — metamorphic

Gneiss Pebble

Gneiss

Siltstone (Siltstone (primarily composed of microcrystalline Quartz and Feldspar)) — sedimentary

Siltstone

Siltstone (primarily composed of microcrystalline Quartz and Feldspar)

Shale (Fissile Mudstone (primarily composed of clay minerals and quartz grains)) — sedimentary

Shale

Fissile Mudstone (primarily composed of clay minerals and quartz grains)

Chert (often called Flint when dark) (Microcrystalline silicon dioxide (SiO2)) — sedimentary

Chert (often called Flint when dark)

Microcrystalline silicon dioxide (SiO2)

Terrazzo (Man-made Composite) (Cementitious or Resin-bound Lithic Composite) — sedimentary (artificial)

Terrazzo (Man-made Composite)

Cementitious or Resin-bound Lithic Composite

sedimentary (artificial)

Shale (sub-type: Carbonaceous Shale) (Lutaceous Sedimentary Rock) — sedimentary

Shale (sub-type: Carbonaceous Shale)

Lutaceous Sedimentary Rock

Quartz Geode (with Agate banding) (Silicon Dioxide (SiO2)) — Sedimentary or Igneous (secondary formation)

Quartz Geode (with Agate banding)

Silicon Dioxide (SiO2)

Sedimentary or Igneous (secondary formation)

Green Aventurine (Green Quartz) (Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)) — Mineral/Metamorphic rock

Green Aventurine (Green Quartz)

Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)

Mineral/Metamorphic rock

Gneiss (High-grade regional metamorphic rock (Foliated)) — metamorphic

Gneiss

High-grade regional metamorphic rock (Foliated)

Quartz (Milky/Crystalline) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky/Crystalline)

Silicon Dioxide (SiO2)

Mica Schist (Mica Schist (predominantly Muscovite or Biotite sheet silicates)) — metamorphic

Mica Schist

Mica Schist (predominantly Muscovite or Biotite sheet silicates)

Chalcedony (Chalcedony (a microcrystalline variety of Quartz, SiO2)) — Mineral

Chalcedony

Chalcedony (a microcrystalline variety of Quartz, SiO2)

Sandstone (Ferruginous) (Arenite (primarily SiO2 with iron oxide staining/cementing)) — sedimentary

Sandstone (Ferruginous)

Arenite (primarily SiO2 with iron oxide staining/cementing)

Carnelian (Red Chalcedony) (Silicon Dioxide (SiO2)) — mineral

Carnelian (Red Chalcedony)

Silicon Dioxide (SiO2)

Quartz (Milky or Smoky variety) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky or Smoky variety)

Silicon Dioxide (SiO2)

Quartz (likely milky quartz or a stained variety) (Silicon Dioxide (SiO₂)) — Mineral

Quartz (likely milky quartz or a stained variety)

Silicon Dioxide (SiO₂)

White Agate / Chalcedony (Silicon Dioxide (SiO2)) — mineral

White Agate / Chalcedony

Silicon Dioxide (SiO2)

Red Jasper (Brecciated or Mottled) (Silicon Dioxide (SiO2) with iron oxide inclusions) — sedimentary

Red Jasper (Brecciated or Mottled)

Silicon Dioxide (SiO2) with iron oxide inclusions

Travertine (used in construction, not a 'specimen' in situ) (Travertine) — Sedimentary

Travertine (used in construction, not a 'specimen' in situ)

Travertine

Red Sandstone (Iron-rich) (Ferruginous Sandstone (variable formula, primarily SiO2 + Fe2O3)) — sedimentary

Red Sandstone (Iron-rich)

Ferruginous Sandstone (variable formula, primarily SiO2 + Fe2O3)

Jasper (likely Lake Superior Jasper) (Jasper (Silicon Dioxide, SiO2)) — sedimentary

Jasper (likely Lake Superior Jasper)

Jasper (Silicon Dioxide, SiO2)

Red Jasper (Plum or Brick variety) (Silicon Dioxide (SiO2) with iron oxide inclusions (Hematite)) — sedimentary (chemical/biological origin)

Red Jasper (Plum or Brick variety)

Silicon Dioxide (SiO2) with iron oxide inclusions (Hematite)

sedimentary (chemical/biological origin)

Banded Gneiss (River Rock/Pebble) (Gneiss (specifically a banded variety often found as a river rock)) — Metamorphic Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

River Rock / Stream Pebble (Fluvial Clast / Rounded Sedimentary Particle) — Sedimentary Rock (possibly composed of various minerals)

River Rock / Stream Pebble

Fluvial Clast / Rounded Sedimentary Particle

Sedimentary Rock (possibly composed of various minerals)

Carnelian Agate (Silicon Dioxide (SiO2) with Iron Oxide impurities) — mineral

Carnelian Agate

Silicon Dioxide (SiO2) with Iron Oxide impurities

Gneiss (with Quartz and Biotite Mica) (Gneiss) — metamorphic

Gneiss (with Quartz and Biotite Mica)

Gneiss

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Ferruginous Sandstone with Ironstone Concretion (Goethite-rich Sandstone (FeO(OH))) — sedimentary

Ferruginous Sandstone with Ironstone Concretion

Goethite-rich Sandstone (FeO(OH))

Quartz Vein in Host Rock (Gneiss/Schist) (Silicon Dioxide (SiO2) within a metamorphic matrix) — metamorphic

Quartz Vein in Host Rock (Gneiss/Schist)

Silicon Dioxide (SiO2) within a metamorphic matrix

Moss Agate (Agate (Silicon Dioxide, SiO2) with dendritic inclusions) — sedimentary

Moss Agate

Agate (Silicon Dioxide, SiO2) with dendritic inclusions

Banded Iron Formation (Jasper-Hematite) (Banded Iron Formation (BIF); composition primarily Hematite (Fe2O3) and Chalcedony/Quartz (SiO2)) — sedimentary

Banded Iron Formation (Jasper-Hematite)

Banded Iron Formation (BIF); composition primarily Hematite (Fe2O3) and Chalcedony/Quartz (SiO2)

Carnelian (a variety of Chalcedony) (Cryptocrystalline Quartz (SiO2) with iron oxide inclusions) — Mineral

Carnelian (a variety of Chalcedony)

Cryptocrystalline Quartz (SiO2) with iron oxide inclusions

River Cobble (likely Quartzite or Limestone) (SiO2 (Quartzite dominant) or CaCO3 (Limestone dominant)) — metamorphic or sedimentary

River Cobble (likely Quartzite or Limestone)

SiO2 (Quartzite dominant) or CaCO3 (Limestone dominant)

metamorphic or sedimentary

Banded Gneiss (Gneiss (High-grade Metamorphic Rock)) — metamorphic

Banded Gneiss

Gneiss (High-grade Metamorphic Rock)

Quartzite (Metamorphosed Quartz Sandstone (SiO2)) — metamorphic

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Quartz (likely macrocrystalline variety) (Quartz (SiO₂)) — Mineral

Quartz (likely macrocrystalline variety)

Quartz (SiO₂)

Leopard Skin Jasper (Orbicular Rhyolite (Silicon Dioxide with various impurities)) — sedimentary

Leopard Skin Jasper

Orbicular Rhyolite (Silicon Dioxide with various impurities)

Yellow Jasper (Jasper (Silicon Dioxide, SiO2)) — sedimentary (or mineraloid)

Yellow Jasper

Jasper (Silicon Dioxide, SiO2)

sedimentary (or mineraloid)

Gneiss (Gneiss (High-grade metamorphic rock)) — metamorphic

Gneiss

Gneiss (High-grade metamorphic rock)

Fluorite and Rose Quartz (Fluorite (CaF2), Rose Quartz (SiO2)) — Mineral

Fluorite and Rose Quartz

Fluorite (CaF2), Rose Quartz (SiO2)