Rock Identifier

Category

Igneous Rock (Volcanic Glass)

Browse igneous rock (volcanic glass) specimens identified by the Rock Identifier community.

Carnelian (Cryptocrystalline Quartz (SiO2)) — mineral

Carnelian

Cryptocrystalline Quartz (SiO2)

Carnelian Agate (Chalcedony (Silicon Dioxide, SiO2)) — mineral

Carnelian Agate

Chalcedony (Silicon Dioxide, SiO2)

Quartzite with Quartz Veins (Quartzite (chiefly SiO2)) — metamorphic

Quartzite with Quartz Veins

Quartzite (chiefly SiO2)

Granite (Granite (Phaneritic intrusive igneous rock)) — igneous

Granite

Granite (Phaneritic intrusive igneous rock)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Granodiorite Pebble (Granodiorite) — igneous

Granodiorite Pebble

Granodiorite

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

Amethyst

Amethyst (SiO2 with Iron impurities)

Chert (Chert / Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Chert / Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Gneiss

Gneiss (High-grade Metamorphic Rock)

Quartz (Quartz (SiO₂)) — Mineral

Quartz

Quartz (SiO₂)

Quartz (likely a weathered/tumbled piece) (Quartz (SiO₂)) — Mineral

Quartz (likely a weathered/tumbled piece)

Quartz (SiO₂)

Dalmatian Stone (Dalmatian Jasper) (Peralkaline Quartz-Feldspar Rock with Arfvedsonite) — igneous

Dalmatian Stone (Dalmatian Jasper)

Peralkaline Quartz-Feldspar Rock with Arfvedsonite

Grey Granite (Phaneritic Felsic Intrusive Igneous Rock) — igneous

Grey Granite

Phaneritic Felsic Intrusive Igneous Rock

Chert (specifically Flint or Gray Chalcedony) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Flint or Gray Chalcedony)

Microcrystalline Quartz (SiO2)

Granite (Granite (Felsic intrusive igneous rock)) — igneous

Granite

Granite (Felsic intrusive igneous rock)

Banded Agate (Silicon Dioxide (SiO2)) — mineral

Banded Agate

Silicon Dioxide (SiO2)

Banded Gneiss (River Rock/Pebble) (Gneiss (specifically a banded variety, likely a orthogneiss or paragneiss depending on parent rock)) — Metamorphic Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety, likely a orthogneiss or paragneiss depending on parent rock)

Metamorphic Rock

Sandstone with Concretions / Liesegang Rings (Arenite with iron oxide banding) — sedimentary

Sandstone with Concretions / Liesegang Rings

Arenite with iron oxide banding

Porphyritic Basalt (Chinese Writing Stone) (Porphyritic Basalt with Feldspar Phenocrysts) — igneous

Porphyritic Basalt (Chinese Writing Stone)

Porphyritic Basalt with Feldspar Phenocrysts

Cullet Glass (Slag Glass) (Amorphous Silicon Dioxide (Industrial Byproduct)) — mineraloid

Cullet Glass (Slag Glass)

Amorphous Silicon Dioxide (Industrial Byproduct)

Chalcedony (Botryoidal Agate vein) (Chalcedony (Microcrystalline Quartz) - SiO2) — mineral

Chalcedony (Botryoidal Agate vein)

Chalcedony (Microcrystalline Quartz) - SiO2

Quartz (chalcedony variety) or Limestone with Quartz Veins (SiO2 (for Quartz/Chalcedony); CaCO3 (for Limestone)) — Mineral or Sedimentary Rock (with mineral inclusions)

Quartz (chalcedony variety) or Limestone with Quartz Veins

SiO2 (for Quartz/Chalcedony); CaCO3 (for Limestone)

Mineral or Sedimentary Rock (with mineral inclusions)

Banded Agate (Agate (Silicon Dioxide - SiO2)) — mineral

Banded Agate

Agate (Silicon Dioxide - SiO2)

Gneiss (Metamorphic Rock) (Gneiss (variable mineral formula primarily containing Quartz, Feldspar, and Mica)) — metamorphic

Gneiss (Metamorphic Rock)

Gneiss (variable mineral formula primarily containing Quartz, Feldspar, and Mica)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Geode (unopened) (Chert / Chalcedony Geode (SiO2)) — sedimentary

Geode (unopened)

Chert / Chalcedony Geode (SiO2)

Granite (Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)) — igneous

Granite

Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)

Dalmatian Stone (Dalmatian Jasper (Peralkaline Quartz-Feldspar Rock)) — igneous

Dalmatian Stone

Dalmatian Jasper (Peralkaline Quartz-Feldspar Rock)

Quartzite (Quartz-rich Cobble) (Quartzite (SiO2)) — metamorphic

Quartzite (Quartz-rich Cobble)

Quartzite (SiO2)

Sodalite Syenite (Sodalite-bearing Syenite (Na8(Al6Si6O24)Cl2)) — igneous

Sodalite Syenite

Sodalite-bearing Syenite (Na8(Al6Si6O24)Cl2)

Chert / Flint (Cryptocrystalline quartz (SiO2)) — Sedimentary

Chert / Flint

Cryptocrystalline quartz (SiO2)

Granodiorite (Granodiorite (Intermediate intrusive igneous rock)) — igneous

Granodiorite

Granodiorite (Intermediate intrusive igneous rock)

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

Quartz (Drusy/Crystalline)

Silicon Dioxide (SiO2)

Quartz (Quartz (Silicon Dioxide - SiO2)) — Mineral

Quartz

Quartz (Silicon Dioxide - SiO2)

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

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Agate (Lace Agate Geode Slice) (Silicon Dioxide (SiO2)) — mineral

Agate (Lace Agate Geode Slice)

Silicon Dioxide (SiO2)

Granodiorite (Granodiorite) — igneous

Granodiorite

Granodiorite

Aventurine (Silicon Dioxide (SiO2) with inclusions of Fuchsite) — mineral

Aventurine

Silicon Dioxide (SiO2) with inclusions of Fuchsite

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

Quartz (Druzy or Geode fragment)

Silicon Dioxide (SiO2)

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

Chalcedony Nodule (Agate/Chert)

Chalcedony (cryptocrystalline Silicon Dioxide, SiO2)

Dendritic Agate (Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions) — mineral

Dendritic Agate

Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions

Glauconitic Sandstone (or Greensand) (Glauconitic Siliciclastic Rock (Containing (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)) — sedimentary

Glauconitic Sandstone (or Greensand)

Glauconitic Siliciclastic Rock (Containing (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)