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

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

Diorite

Diorite (Intermediate intrusive igneous rock)

Diorite (Polished River Pebble) (Diorite (Intermediate intrusive igneous rock)) — igneous

Diorite (Polished River Pebble)

Diorite (Intermediate intrusive igneous rock)

Granodiorite (Phaneritic Plutonic Rock (Intermediate)) — igneous

Granodiorite

Phaneritic Plutonic Rock (Intermediate)

Basalt (Basalt) — igneous

Basalt

Basalt

Polished pink granite cobble (Granite, chiefly potassium feldspar, plagioclase, quartz, and biotite/hornblende) — igneous

Polished pink granite cobble

Granite, chiefly potassium feldspar, plagioclase, quartz, and biotite/hornblende

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

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Granite Water-Worn Pebble (Intermediate to Felsic Phaneritic Igneous Rock) — igneous

Granite Water-Worn Pebble

Intermediate to Felsic Phaneritic Igneous Rock

Likely basalt (possibly scoriaceous basalt) (Basalt; chiefly plagioclase feldspar, pyroxene, and commonly olivine, with minor iron–titanium oxides) — igneous

Likely basalt (possibly scoriaceous basalt)

Basalt; chiefly plagioclase feldspar, pyroxene, and commonly olivine, with minor iron–titanium oxides

Wonderstone (Rhyolite (Silicon Dioxide with Iron Oxide impurities)) — igneous

Wonderstone

Rhyolite (Silicon Dioxide with Iron Oxide impurities)

Thunderegg (Agetized Geode nodule) (Rhyolitic Agate Nodule (SiO2 filling volcanic cavities)) — igneous

Thunderegg (Agetized Geode nodule)

Rhyolitic Agate Nodule (SiO2 filling volcanic cavities)

Tumbled Stones Collection (Tiger's Eye, Snowflake Obsidian, Aventurine, etc.) (Silica minerals (primarily SiO2)) — mineral

Tumbled Stones Collection (Tiger's Eye, Snowflake Obsidian, Aventurine, etc.)

Silica minerals (primarily SiO2)

Small tumbled dark stone, possibly basalt or slag (Likely fine-grained basalt; exact identification is uncertain from the photograph) — igneous

Small tumbled dark stone, possibly basalt or slag

Likely fine-grained basalt; exact identification is uncertain from the photograph

Basalt with Quartz/Calcite Veins (Aphanitic Mafic Igneous Rock with Hydrothermal Veining) — igneous

Basalt with Quartz/Calcite Veins

Aphanitic Mafic Igneous Rock with Hydrothermal Veining

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

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

Unidentified weathered rock, possibly quartz-bearing granite or rhyolite (Indeterminate; likely quartz–feldspar-rich silicate rock) — igneous

Unidentified weathered rock, possibly quartz-bearing granite or rhyolite

Indeterminate; likely quartz–feldspar-rich silicate rock

Granite Pebble (River Rock) (Phaneritic Felsic Igneous Rock) — igneous

Granite Pebble (River Rock)

Phaneritic Felsic Igneous Rock

Agate Nodule (Silicon Dioxide (Quartz/Chalcedony), SiO2) — sedimentary

Agate Nodule

Silicon Dioxide (Quartz/Chalcedony), SiO2

Basalt with Plagioclase Phenocrysts (Porphyritic Basalt) — igneous

Basalt with Plagioclase Phenocrysts

Porphyritic Basalt

Gabbro (Phaneritic Basic Igneous Rock (Gabbro)) — igneous

Gabbro

Phaneritic Basic Igneous Rock (Gabbro)

Granite boulder (Granite, composed mainly of quartz, alkali feldspar, plagioclase, and minor mica/amphibole) — igneous

Granite boulder

Granite, composed mainly of quartz, alkali feldspar, plagioclase, and minor mica/amphibole

Tumbled black-and-white stone, likely dalmatian jasper (Quartz-rich porphyritic rhyolite (commercially called dalmatian jasper), with black aegirine/arfvedsonite-like inclusions) — igneous

Tumbled black-and-white stone, likely dalmatian jasper

Quartz-rich porphyritic rhyolite (commercially called dalmatian jasper), with black aegirine/arfvedsonite-like inclusions

Obsidian (Volcanic Glass (Amorphous Silica)) — igneous

Obsidian

Volcanic Glass (Amorphous Silica)

Obsidian (Volcanic Glass (predominantly SiO2)) — igneous

Obsidian

Volcanic Glass (predominantly SiO2)

Riverstone (likely Basalt or Greywacke) (Extrusive Magmatic Basalt) — igneous

Riverstone (likely Basalt or Greywacke)

Extrusive Magmatic Basalt

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

Basalt

Basalt (Extrusive Mafic Igneous Rock)

Basalt-Amugydule (Amygdaloidal Basalt) (Aphanitic Mafic Igneous Rock with Vesicle Infillings) — igneous

Basalt-Amugydule (Amygdaloidal Basalt)

Aphanitic Mafic Igneous Rock with Vesicle Infillings

Tumbled Agate Pebble (Silicon Dioxide (SiO2)) — sedimentary

Tumbled Agate Pebble

Silicon Dioxide (SiO2)

Turtleback Rock (Brecciated Diabase / Granite) (Brecciated hypabyssal intrusive rock) — igneous

Turtleback Rock (Brecciated Diabase / Granite)

Brecciated hypabyssal intrusive rock

Clear Quartz Point (Silicon Dioxide (SiO2)) — mineral

Clear Quartz Point

Silicon Dioxide (SiO2)

Peridotite (Dunite) (Peridotite (mostly Olivine: (Mg,Fe)2SiO4)) — igneous

Peridotite (Dunite)

Peridotite (mostly Olivine: (Mg,Fe)2SiO4)

Black tumbled stone, likely basalt or black jasper (Most consistent with fine-grained basalt (mainly plagioclase and pyroxene); exact identification requires testing) — igneous

Black tumbled stone, likely basalt or black jasper

Most consistent with fine-grained basalt (mainly plagioclase and pyroxene); exact identification requires testing

Scoria (Lava Rock) (Scoria (vesicular basaltic rock)) — igneous

Scoria (Lava Rock)

Scoria (vesicular basaltic rock)

Que Sera Stone (Llanite) (Rhyolite Porphyry with Blue Quartz and Feldspar) — igneous

Que Sera Stone (Llanite)

Rhyolite Porphyry with Blue Quartz and Feldspar

Basalt with Amygdules (Amygdaloidal Basalt) — igneous

Basalt with Amygdules

Amygdaloidal Basalt

Basalt (Fine-grained mafic volcanic rock, chiefly plagioclase feldspar, pyroxene, and commonly olivine) — igneous

Basalt

Fine-grained mafic volcanic rock, chiefly plagioclase feldspar, pyroxene, and commonly olivine

Weathered granitic rock (Granite or granodiorite; primarily quartz (SiO₂), feldspar, and mica) — igneous

Weathered granitic rock

Granite or granodiorite; primarily quartz (SiO₂), feldspar, and mica

Basalt (Basalt (Mafic Extrusive)) — igneous

Basalt

Basalt (Mafic Extrusive)

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

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

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

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Basalt (Vesicular/Waterworn) (Basalt (Mafic Extrusive Igneous Rock)) — igneous

Basalt (Vesicular/Waterworn)

Basalt (Mafic Extrusive Igneous Rock)

Vesicular Basalt (Scoria) (Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)) — igneous

Vesicular Basalt (Scoria)

Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)