Rock Identifier

Category

The Purple Specimen Is A Mineral (Amethyst); The White Specimen Is A Sedimentary Rock (Limestone Or Marble).

Browse the purple specimen is a mineral (amethyst); the white specimen is a sedimentary rock (limestone or marble). specimens identified by the Rock Identifier community.

Chert (and Chert Geode) (Silicon Dioxide (SiO2)) — sedimentary

Chert (and Chert Geode)

Silicon Dioxide (SiO2)

Chert (Jasper/Flint variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Quartz Geode Fragment (Silicon Dioxide (SiO2)) — mineral

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Black Opal (Hydrated Amorphous Silica (SiO2·nH2O)) — Mineral

Black Opal

Hydrated Amorphous Silica (SiO2·nH2O)

Sandstone (Quartz-rich) (Clastic sedimentary rock (SiO2 primary)) — sedimentary

Sandstone (Quartz-rich)

Clastic sedimentary rock (SiO2 primary)

Sandstone (likely Quartzose type) (Clastic sedimentary rock (primarily SiO2)) — sedimentary

Sandstone (likely Quartzose type)

Clastic sedimentary rock (primarily SiO2)

Quartz with Iron Staining (Silicon Dioxide (SiO2) with Ferruginous Oxides) — mineral

Quartz with Iron Staining

Silicon Dioxide (SiO2) with Ferruginous Oxides

Chevron Amethyst (Silicon Dioxide (SiO2) with iron impurities) — mineral

Chevron Amethyst

Silicon Dioxide (SiO2) with iron impurities

Amethyst (Pale/Lavender variety) (Silicon Dioxide (SiO2)) — mineral

Amethyst (Pale/Lavender variety)

Silicon Dioxide (SiO2)

Sandstone Beach Pebble (Clastic sedimentary rock (SiO2 with iron oxide cement)) — sedimentary

Sandstone Beach Pebble

Clastic sedimentary rock (SiO2 with iron oxide cement)

Sandstone (Weathered Cobble) (Clastic Sedimentary Rock (primarily SiO2)) — sedimentary

Sandstone (Weathered Cobble)

Clastic Sedimentary Rock (primarily SiO2)

Amethyst (Silicon Dioxide (SiO2) with Fe3+ impurities) — mineral

Amethyst

Silicon Dioxide (SiO2) with Fe3+ impurities

Amethyst (Silicon dioxide (variant with ferric iron impurities), SiO2) — mineral

Amethyst

Silicon dioxide (variant with ferric iron impurities), SiO2

Green Calcite (Calcium Carbonate (CaCO3)) — mineral

Green Calcite

Calcium Carbonate (CaCO3)

Sandstone (with Iron Staining) (Clastic sedimentary rock (SiO2 with Fe2O3 impurities)) — sedimentary

Sandstone (with Iron Staining)

Clastic sedimentary rock (SiO2 with Fe2O3 impurities)

Agate (Silicon Dioxide (SiO2) - variety Chalcedony) — mineral

Agate

Silicon Dioxide (SiO2) - variety Chalcedony

Amethyst (Amethyst (Silicon Dioxide - SiO2 with ferric iron impurities)) — mineral

Amethyst

Amethyst (Silicon Dioxide - SiO2 with ferric iron impurities)

Blue Agate (Dyed) (Silicon Dioxide (SiO2) - Variety of Chalcedony) — mineral

Blue Agate (Dyed)

Silicon Dioxide (SiO2) - Variety of Chalcedony

Amethyst (Amethyst (SiO2 with iron impurities)) — mineral

Amethyst

Amethyst (SiO2 with iron impurities)

Chert (specifically Yellow/Honey Jasper variety) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Yellow/Honey Jasper variety)

Cryptocrystalline Quartz (SiO2)

Gneiss (specifically Pink Gneiss) (Gneiss (high-grade regional metamorphic rock)) — metamorphic

Gneiss (specifically Pink Gneiss)

Gneiss (high-grade regional metamorphic rock)

Calcite Geode (Calcium Carbonate (CaCO3)) — mineral

Calcite Geode

Calcium Carbonate (CaCO3)

Breciated Chert (Brecciated Chert (Microcrystalline Quartz, SiO2)) — sedimentary

Breciated Chert

Brecciated Chert (Microcrystalline Quartz, SiO2)

Quartz Vein in Host Rock (Silicon Dioxide (SiO2)) — mineral / metamorphic

Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

mineral / metamorphic

Blue Kyanite (Kyanite (Al2SiO5)) — mineral

Blue Kyanite

Kyanite (Al2SiO5)

Honey Calcite (Calcium Carbonate (CaCO3)) — mineral

Honey Calcite

Calcium Carbonate (CaCO3)

Amethyst (Silicon Dioxide (SiO2) with iron impurities) — mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Chert (with Desert Varnish/Iron Stain) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (with Desert Varnish/Iron Stain)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Honey Chert / Flint) (Silicon Dioxide (SiO2) - Cryptocrystalline Quartz) — sedimentary

Chert (Honey Chert / Flint)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Sandstone (Water-worn) (Arenite) — sedimentary

Sandstone (Water-worn)

Arenite

Amethyst (SiO2 (Silicon Dioxide) - Purple variety of Quartz) — mineral

Amethyst

SiO2 (Silicon Dioxide) - Purple variety of Quartz

Chert (Jasper variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper variety)

Microcrystalline Quartz (SiO2)

Sandstone (Ferruginous) (Arenite with Iron Oxide cement (SiO2 + Fe2O3)) — sedimentary

Sandstone (Ferruginous)

Arenite with Iron Oxide cement (SiO2 + Fe2O3)

Milky Quartz (with Iron Oxide staining) (Quartz (Silicon Dioxide - SiO2)) — mineral

Milky Quartz (with Iron Oxide staining)

Quartz (Silicon Dioxide - SiO2)

Sandstone (Ferruginous) (Arenite (SiO2 with Fe2O3 inclusions)) — sedimentary

Sandstone (Ferruginous)

Arenite (SiO2 with Fe2O3 inclusions)

Limonite (often after Hematite or Goethite) (Limonite (FeO(OH)·nH2O)) — mineral

Limonite (often after Hematite or Goethite)

Limonite (FeO(OH)·nH2O)

Sandstone (Ferruginous) (Arenite (primarily SiO2 with Fe2O3 cement)) — sedimentary

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 cement)

Quartz (Iron-stained) (Silicon Dioxide (SiO2)) — mineral

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Yellow Calcite (Calcium Carbonate (CaCO3)) — mineral

Yellow Calcite

Calcium Carbonate (CaCO3)

Amethyst (Silicon Dioxide (SiO2) with trace Iron (Fe3+)) — mineral

Amethyst

Silicon Dioxide (SiO2) with trace Iron (Fe3+)

Sandstone (Clastic Sedimentary Rock (composed mostly of quartz and/or feldspar)) — sedimentary

Sandstone

Clastic Sedimentary Rock (composed mostly of quartz and/or feldspar)

Basalt (Purple-tinted scoria/vesicular variety) (Extrusive mafic igneous rock (SiO2 range 45–52%)) — igneous

Basalt (Purple-tinted scoria/vesicular variety)

Extrusive mafic igneous rock (SiO2 range 45–52%)