Rock Identifier

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Rock

Browse rock specimens identified by the Rock Identifier community.

Rough Tanzanite (Zoisite (Ca2Al3(SiO4)3(OH))) — mineral

Rough Tanzanite

Zoisite (Ca2Al3(SiO4)3(OH))

Chert (Flint) (Chert (SiO2)) — sedimentary

Chert (Flint)

Chert (SiO2)

Sandstone Concretion (Clastic sedimentary rock (primarily Quartz SiO2)) — sedimentary

Sandstone Concretion

Clastic sedimentary rock (primarily Quartz SiO2)

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

Amethyst

Silicon Dioxide (SiO2) with Iron impurities

Banded Chert or Agate (Silicon Dioxide (SiO2)) — sedimentary

Banded Chert or Agate

Silicon Dioxide (SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Diabase (Diabase (also known as Dolerite)) — igneous

Diabase

Diabase (also known as Dolerite)

Chert (Iron-stained) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Iron-stained)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically Yellow Jasper/Flint) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Yellow Jasper/Flint)

Microcrystalline Quartz (SiO2)

Pink Opal (Amorphous Hydrous Silica (SiO2·nH2O)) — mineral

Pink Opal

Amorphous Hydrous Silica (SiO2·nH2O)

Olivine/Peridot (Magnesium Iron Silicate (Mg,Fe)2SiO4) — mineral

Olivine/Peridot

Magnesium Iron Silicate (Mg,Fe)2SiO4

Amygdaloidal Basalt (Amygdaloidal Basalt (Mafic extrusive volcanic rock with secondary mineral infilling)) — igneous

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic extrusive volcanic rock with secondary mineral infilling)

Banded Chert (Agate-like Flint) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Banded Chert (Agate-like Flint)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

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

Amethyst (Rough)

Silicon Dioxide with iron impurities (SiO2)

Opalite (Man-made Glass (SiO2 + additives)) — mineraloid (synthetic)

Opalite

Man-made Glass (SiO2 + additives)

mineraloid (synthetic)

Quartz Veined Siltstone or Graywacke (Clastic Sedimentary Rock with Quartz (SiO2) veining) — sedimentary

Quartz Veined Siltstone or Graywacke

Clastic Sedimentary Rock with Quartz (SiO2) veining

Amygdaloidal Basalt with Agate/Chalcedony Infills (Amygdaloidal Basalt (Composition: SiO2 and (Mg,Fe)2SiO4 in matrix; SiO2 in amygdule)) — igneous

Amygdaloidal Basalt with Agate/Chalcedony Infills

Amygdaloidal Basalt (Composition: SiO2 and (Mg,Fe)2SiO4 in matrix; SiO2 in amygdule)

Limestone Breccia (Sedimentary Breccia (Calcareous)) — sedimentary

Limestone Breccia

Sedimentary Breccia (Calcareous)

Chert / Jasper / Agate (Chalcedony Group) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert / Jasper / Agate (Chalcedony Group)

Microcrystalline Quartz (SiO2)

Amygdaloidal Basalt (Amygdaloidal Basalt containing Zeolite or Quartz (SiO2/Silicates)) — igneous

Amygdaloidal Basalt

Amygdaloidal Basalt containing Zeolite or Quartz (SiO2/Silicates)

Yellow Ochre / Limonite (Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)) — mineral

Yellow Ochre / Limonite

Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)

Chert (and/or River Pebble) (Microcrystalline silica (SiO2)) — sedimentary

Chert (and/or River Pebble)

Microcrystalline silica (SiO2)

Emerald In Matrix (Quartz/Calcite) (Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities) — mineral

Emerald In Matrix (Quartz/Calcite)

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Chalcedony (Botryoidal) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Botryoidal)

Silicon Dioxide (SiO2)

Specular Hematite (Specularite (Fe2O3)) — mineral

Specular Hematite

Specularite (Fe2O3)

Amethyst (Amethyst (Silicon Dioxide, SiO2)) — mineral

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Granodiorite (Granodiorite (Intermediate to Felsic Intrusive Rock)) — igneous

Granodiorite

Granodiorite (Intermediate to Felsic Intrusive Rock)

Quartz (specifically Clear Quartz or Rock Crystal) (Silicon Dioxide (SiO2)) — mineral

Quartz (specifically Clear Quartz or Rock Crystal)

Silicon Dioxide (SiO2)

Decomposed Granite (Grano-diorite/Granite-residuum (SiO2 primary)) — igneous

Decomposed Granite

Grano-diorite/Granite-residuum (SiO2 primary)

Quartz (Druzy or Geode fragment) (Silicon Dioxide (SiO2)) — mineral

Quartz (Druzy or Geode fragment)

Silicon Dioxide (SiO2)

Blue Apatite (Fluorapatite (Ca5(PO4)3F)) — mineral

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Chalcedony Nodule (Agate/Chert) (Chalcedony (cryptocrystalline Silicon Dioxide, SiO2)) — mineral

Chalcedony Nodule (Agate/Chert)

Chalcedony (cryptocrystalline Silicon Dioxide, SiO2)

Green Opal (Hydrated Silica (SiO2·nH2O)) — mineraloid

Green Opal

Hydrated Silica (SiO2·nH2O)

Pumice (Pumice (a highly vesicular volcanic glass)) — igneous

Pumice

Pumice (a highly vesicular volcanic glass)

Muscovite Mica (Golden/Yellow variety) (KAl2(AlSi3O10)(F,OH)2) — mineral

Muscovite Mica (Golden/Yellow variety)

KAl2(AlSi3O10)(F,OH)2

Scoria (Lava Rock) (Vesicular Basalt / Scoria) — igneous

Scoria (Lava Rock)

Vesicular Basalt / Scoria

Diorite (Salt and Pepper Rock) (Diorite) — igneous

Diorite (Salt and Pepper Rock)

Diorite

Clear Quartz (Rock Crystal) (Quartz (Silicon Dioxide, SiO2)) — mineral

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

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

Agate

Silicon Dioxide (SiO2) - variety of Chalcedony

Red Sandstone (Arenite (Ferruginous Sandstone)) — sedimentary

Red Sandstone

Arenite (Ferruginous Sandstone)

Sandstone with Quartz Vein (Arenite with Quartz (SiO2) Infilling) — sedimentary

Sandstone with Quartz Vein

Arenite with Quartz (SiO2) Infilling

Ferruginous Sandstone (Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)) — sedimentary

Ferruginous Sandstone

Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)