Rock Identifier

Category

Glass

Browse glass specimens identified by the Rock Identifier community.

Learn about Glass in the encyclopedia

Sideromelane

Black Obsidian

Maskelynite

Tachylite

Obsidian

Hyalite Opal

Perlite

Opalite

Macusanite

Pink Obsidian

Goldstone

Palagonite

Muscovite Mica (in Quartz/Feldspar Matrix) (Muscovite - KAl2(AlSi3O10)(OH)2) — mineral

Muscovite Mica (in Quartz/Feldspar Matrix)

Muscovite - KAl2(AlSi3O10)(OH)2

Muscovite (Muscovite (KAl2(AlSi3O10)(OH)2)) — mineral

Muscovite

Muscovite (KAl2(AlSi3O10)(OH)2)

Muscovite Mica (Muscovite (KAl2(AlSi3O10)(OH)2)) — mineral

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

Muscovite Mica (Muscovite (KAl2(AlSi3O10)(OH)2)) — mineral

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

Chert (specifically Gray Chert) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Gray Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Mica (Muscovite) (Potassium aluminum silicate - KAl2(AlSi3O10)(OH)2) — mineral

Mica (Muscovite)

Potassium aluminum silicate - KAl2(AlSi3O10)(OH)2

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

Tumbled Quartz Pebble

Silicon Dioxide (SiO2)

Snowflake Obsidian (Volcanic Glass with Spherulite Inclusions (70–75% SiO2)) — igneous

Snowflake Obsidian

Volcanic Glass with Spherulite Inclusions (70–75% SiO2)

Tumbled rose quartz (probable) (Quartz, silicon dioxide (SiO₂), pink variety) — mineral

Tumbled rose quartz (probable)

Quartz, silicon dioxide (SiO₂), pink variety

Sea Glass (Man-made vitreous material (silica glass)) — sedimentary

Sea Glass

Man-made vitreous material (silica glass)

Sea Glass (Man-made silicate glass) — sedimentary

Sea Glass

Man-made silicate glass

Sea Glass (Man-made silicate glass) — mineral

Sea Glass

Man-made silicate glass

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Chert (Flint Gravel) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Flint Gravel)

Silicon Dioxide (SiO2)

Chert (Flint) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Flint)

Microcrystalline Quartz (SiO2)

Snowflake Obsidian (Volcanic Glass with Cristobalite inclusions (SiO2)) — igneous

Snowflake Obsidian

Volcanic Glass with Cristobalite inclusions (SiO2)

Opalite (Man-made opalescent glass (SiO2 + metal oxides)) — mineral (synthetic)

Opalite

Man-made opalescent glass (SiO2 + metal oxides)

mineral (synthetic)

Slag (Ferrous slag (by-product of iron smelting)) — Mineraloid / Anthropogenic

Slag

Ferrous slag (by-product of iron smelting)

Mineraloid / Anthropogenic

Opalite (Man-made Glass) (Synthetic Opalised Glass) — mineral

Opalite (Man-made Glass)

Synthetic Opalised Glass

Snowflake Obsidian (Volcanic glass with Cristobalite inclusions (70–75% SiO2)) — Igneous

Snowflake Obsidian

Volcanic glass with Cristobalite inclusions (70–75% SiO2)

Red Quartz (Tumbled) (Silicon Dioxide with Iron Oxide inclusions (SiO2)) — mineral

Red Quartz (Tumbled)

Silicon Dioxide with Iron Oxide inclusions (SiO2)

Rock crystal (clear quartz), possibly cloudy quartz (Quartz, silicon dioxide (SiO₂)) — mineral

Rock crystal (clear quartz), possibly cloudy quartz

Quartz, silicon dioxide (SiO₂)

Snowflake obsidian cabochon (Obsidian (volcanic glass), SiO₂-rich; white areas are cristobalite/spherulitic devitrification) — igneous

Snowflake obsidian cabochon

Obsidian (volcanic glass), SiO₂-rich; white areas are cristobalite/spherulitic devitrification

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

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Obsidian (volcanic glass) (Obsidian; predominantly silica-rich volcanic glass, commonly rhyolitic in composition) — igneous

Obsidian (volcanic glass)

Obsidian; predominantly silica-rich volcanic glass, commonly rhyolitic in composition

Snowflake Obsidian (Volcanic Glass (SiO2) with Cristobalite inclusions) — igneous

Snowflake Obsidian

Volcanic Glass (SiO2) with Cristobalite inclusions

Clear faceted gemstone, likely quartz (rock crystal) (Quartz, silicon dioxide (SiO₂); visual identification is uncertain because the stone is heavily faceted and photographed with flash) — gemstone

Clear faceted gemstone, likely quartz (rock crystal)

Quartz, silicon dioxide (SiO₂); visual identification is uncertain because the stone is heavily faceted and photographed with flash

Polished mahogany obsidian (Volcanic glass; rhyolitic obsidian, commonly with iron-oxide coloration) — igneous

Polished mahogany obsidian

Volcanic glass; rhyolitic obsidian, commonly with iron-oxide coloration

Rounded white pebble, likely quartzite or limestone (Probable quartzite (microcrystalline quartz, SiO₂) or calcitic limestone (CaCO₃)) — sedimentary

Rounded white pebble, likely quartzite or limestone

Probable quartzite (microcrystalline quartz, SiO₂) or calcitic limestone (CaCO₃)

Polished/tumbled light-colored stone, possibly quartzite or marble (Uncertain; likely quartzite (mostly SiO₂) or calcite marble (CaCO₃)) — metamorphic

Polished/tumbled light-colored stone, possibly quartzite or marble

Uncertain; likely quartzite (mostly SiO₂) or calcite marble (CaCO₃)

Clear quartz crystal (likely vein quartz) (Quartz, silicon dioxide (SiO₂), most likely colorless macrocrystalline quartz) — mineral

Clear quartz crystal (likely vein quartz)

Quartz, silicon dioxide (SiO₂), most likely colorless macrocrystalline quartz

Muscovite Mica (Muscovite (KAl2(AlSi3O10)(OH)2)) — mineral

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

Tumbled pink-and-gray quartzite (probable) (Quartzite; predominantly microcrystalline quartz (SiO₂), with iron-oxide and other mineral impurities) — metamorphic

Tumbled pink-and-gray quartzite (probable)

Quartzite; predominantly microcrystalline quartz (SiO₂), with iron-oxide and other mineral impurities

Muscovite Mica (on Quartz Matrix) (Muscovite - KAl2(AlSi3O10)(OH)2) — mineral

Muscovite Mica (on Quartz Matrix)

Muscovite - KAl2(AlSi3O10)(OH)2

Muscovite Mica (Muscovite - KAl2(AlSi3O10)(OH)2) — mineral

Muscovite Mica

Muscovite - KAl2(AlSi3O10)(OH)2

Green Aventurine (Aventurine Quartz (SiO2 with Fuchsite inclusions)) — metamorphic

Green Aventurine

Aventurine Quartz (SiO2 with Fuchsite inclusions)

Snowflake Obsidian (Volcanic glass with Spherulite inclusions (SiO2)) — igneous

Snowflake Obsidian

Volcanic glass with Spherulite inclusions (SiO2)

Clear Quartz (Silicon Dioxide (SiO2)) — mineral

Clear Quartz

Silicon Dioxide (SiO2)

Quartz (Milky/Clear variety) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky/Clear variety)

Silicon Dioxide (SiO2)

Faceted colorless gemstone, likely quartz (rock crystal) or synthetic glass imitation (Quartz: silicon dioxide (SiO₂), trigonal crystal system; exact identity cannot be confirmed visually) — gemstone

Faceted colorless gemstone, likely quartz (rock crystal) or synthetic glass imitation

Quartz: silicon dioxide (SiO₂), trigonal crystal system; exact identity cannot be confirmed visually

Chert (Flint/Jasper) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Flint/Jasper)

Silicon Dioxide (SiO2)