Rock Identifier

Category

Igneous Rock (Volcanic Glass)

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

Learn about Igneous Rock (Volcanic Glass) in the encyclopedia

Rock Gypsum

Coral Rock

Asphalt Rock

Rock Salt

Calc-Silicate Rock

Calc-Silicate Rock

Talc-carbonate Rock

Talc-carbonate Rock

Black Obsidian

Obsidian

Pink Obsidian

Sideromelane

Carbonatite

Tachylite

Porphyritic Basalt (Basalt (with plagioclase or k-feldspar phenocrysts)) — igneous

Porphyritic Basalt

Basalt (with plagioclase or k-feldspar phenocrysts)

Basalt with Plagioclase Phenocrysts (Porphyritic Basalt) — igneous

Basalt with Plagioclase Phenocrysts

Porphyritic Basalt

Diorite (Intrusive Igneous Rock (Intermediate Composition)) — igneous

Diorite

Intrusive Igneous Rock (Intermediate Composition)

White Quartz (Silicon Dioxide (SiO2)) — mineral

White Quartz

Silicon Dioxide (SiO2)

Diorite (Diorite (Intermediate intrusive igneous rock)) — igneous

Diorite

Diorite (Intermediate intrusive igneous rock)

Diorite (Polished Cobble) (Diorite (Intermediate intrusive igneous rock)) — Igneous

Diorite (Polished Cobble)

Diorite (Intermediate intrusive igneous rock)

Amethyst (Silicon Dioxide (SiO2)) — mineral

Amethyst

Silicon Dioxide (SiO2)

Dalmatian Jasper (Peralkaline Rhyolite (composed of Quartz, Feldspar, and Arfvedsonite)) — igneous

Dalmatian Jasper

Peralkaline Rhyolite (composed of Quartz, Feldspar, and Arfvedsonite)

Pink Granite (Phaneritic Felsic Igneous Rock) — igneous

Pink Granite

Phaneritic Felsic Igneous Rock

Chalcedony (Cryptocrystalline Quartz (SiO2)) — mineral

Chalcedony

Cryptocrystalline Quartz (SiO2)

Basalt (Basalt (Aphanitic Mafic Igneous Rock)) — igneous

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

Weathered basalt or iron-rich river cobble (Basalt, likely with iron-oxide staining; exact identification requires testing) — igneous

Weathered basalt or iron-rich river cobble

Basalt, likely with iron-oxide staining; exact identification requires testing

Peridotite (Peridotite (composed largely of Olivine (Mg,Fe)2SiO4 and Pyroxene)) — igneous

Peridotite

Peridotite (composed largely of Olivine (Mg,Fe)2SiO4 and Pyroxene)

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

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Polished Black Onyx (or Obsidian) (Silicon Dioxide (SiO2)) — mineral

Polished Black Onyx (or Obsidian)

Silicon Dioxide (SiO2)

Basalt (Mafic volcanic rock (consisting mostly of plagioclase, pyroxene, and olivine)) — igneous

Basalt

Mafic volcanic rock (consisting mostly of plagioclase, pyroxene, and olivine)

Diorite (Diorite (Intermediate Plutonic Rock)) — igneous

Diorite

Diorite (Intermediate Plutonic Rock)

Basalt with Limonite stains (Extrusive mafic igneous rock; Limonite (FeO(OH)·nH2O)) — igneous

Basalt with Limonite stains

Extrusive mafic igneous rock; Limonite (FeO(OH)·nH2O)

Basalt (Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)) — igneous

Basalt

Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)

Red Jasper with Quartz (Microcrystalline Quartz (SiO2) with Hematite inclusions) — sedimentary

Red Jasper with Quartz

Microcrystalline Quartz (SiO2) with Hematite inclusions

Milky Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Milky Quartz Pebble

Silicon Dioxide (SiO2)

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

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

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

Quartz Crystal Fragment

Silicon Dioxide (SiO2)

Peridotite (Ultramafic intrusive rock (Peridotite / Dunite)) — igneous

Peridotite

Ultramafic intrusive rock (Peridotite / Dunite)

Rounded basalt cobble (Basalt, a fine-grained mafic volcanic rock composed mainly of plagioclase and pyroxene, commonly with minor olivine and iron oxides) — igneous

Rounded basalt cobble

Basalt, a fine-grained mafic volcanic rock composed mainly of plagioclase and pyroxene, commonly with minor olivine and iron oxides

Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble

Silicon Dioxide (SiO2)

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

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Basalt (Basalt (predominantly Plagioclase Feldspar and Pyroxene)) — igneous

Basalt

Basalt (predominantly Plagioclase Feldspar and Pyroxene)

Rounded gray river cobble (Likely basalt or fine-grained mafic volcanic rock; exact identification requires testing) — igneous

Rounded gray river cobble

Likely basalt or fine-grained mafic volcanic rock; exact identification requires testing

Chalcedony (specifically Agate and Carnelian variety) (Silicon Dioxide (SiO2) - Cryptocrystalline Quartz) — mineral

Chalcedony (specifically Agate and Carnelian variety)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Jasper (Silicon Dioxide (SiO2)) — sedimentary

Jasper

Silicon Dioxide (SiO2)

Quartz geode (Microcrystalline and crystalline quartz (SiO₂), likely chalcedony-lined geode) — mineral

Quartz geode

Microcrystalline and crystalline quartz (SiO₂), likely chalcedony-lined geode

Pumice or Tufa/Travertine (Pumice (if igneous) or Calcareous Tufa (if sedimentary)) — igneous/sedimentary

Pumice or Tufa/Travertine

Pumice (if igneous) or Calcareous Tufa (if sedimentary)

igneous/sedimentary

Basalt with Quartz/Calcite Inclusion (Aphanitic Mafic Igneous Rock (Basalt) with SiO2 or CaCO3 vein) — igneous

Basalt with Quartz/Calcite Inclusion

Aphanitic Mafic Igneous Rock (Basalt) with SiO2 or CaCO3 vein

Jasper (likely Brecciated or Multi-colored) (Jasper (SiO2)) — sedimentary

Jasper (likely Brecciated or Multi-colored)

Jasper (SiO2)

Basalt (Basalt (Mafic Extrusive Igneous Rock)) — igneous

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Basalt (Basalt (Aphanitic extrusive igneous rock)) — igneous

Basalt

Basalt (Aphanitic extrusive igneous rock)

Weathered vesicular basalt (probable) (Basalt; primarily plagioclase, clinopyroxene, and iron-rich olivine, with secondary weathering minerals) — igneous

Weathered vesicular basalt (probable)

Basalt; primarily plagioclase, clinopyroxene, and iron-rich olivine, with secondary weathering minerals

Small white mineral fragment (Indeterminate; possibly quartz, calcite, or feldspar) — mineral

Small white mineral fragment

Indeterminate; possibly quartz, calcite, or feldspar

Black Sapphire (Basaltic Blue Sapphire) (Corundum (Al2O3)) — mineral

Black Sapphire (Basaltic Blue Sapphire)

Corundum (Al2O3)

Obsidian (Volcanic glass (SiO2 - Silicon Dioxide with impurities)) — igneous

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with impurities)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)