Igneous Rock (Volcanic Glass)

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

Dalmatian Jasper (Dalmatian Stone)

Perthitic feldspar with Arfvedsonite inclusions

igneous

Pink Granite

Phaneritic Felsic Igneous Rock (Granite)

igneous

Agate Geode Slice (with Druzy Quartz)

Silicon Dioxide (SiO2)

mineral

Quartzite (River Pebble)

Meta-quartzite (composed primarily of SiO2)

metamorphic

Crazy Lace Agate

Silicon Dioxide (SiO2) - Chalcedony variety

mineral

Carnelian (Carnelian Agate)

Silicon dioxide (SiO2) - a variety of Chalcedony

mineral

Banded Agate

Microcrystalline Quartz (SiO2) with impurities

mineral

Granite (Specimen: Logan Rock)

Phaneritic plutonic igneous rock (mainly Quartz, Feldspar, and Mica)

igneous

Leopard Skin Jasper

Jasper (Silicon Dioxide with impurities), SiO2

sedimentary

Granodiorite

Granodiorite (containing Plagioclase, Quartz, and Biotite)

igneous

Granodiorite with Biotite Mica

Granodiorite (containing Quartz, Plagioclase Feldspar, and Biotite Mica)

igneous

Sandstone

Quartz Sandstone (predominantly)

Sedimentary

Fossiliferous Chert with Brachiopod Impression

Chert (SiO2) containing Brachiopoda fossil remains

sedimentary

Clear Quartz (or Rock Crystal)

Quartz (SiO₂)

Mineral

Olivine (Peridot)

Magnesium Iron Silicate (Mg, Fe)2SiO4

mineral

Cullet (Slag Glass)

Amorphous Silica (Industrial byproduct)

mineraloid

Unakite

Epidotized Granite

metamorphic

Mica Group Minerals

There isn't a single scientific name as 'Mica' refers to a group of phyllosilicate minerals. Common scientific names include Muscovite (KAl₂ (AlSi₃O₁₀)(OH)₂), Biotite (K(Mg,Fe)₃AlSi₃O₁₀(OH)₂), Phlogopite (KMg₃AlSi₃O₁₀(OH)₂), and Lepidolite (K(Li,Al)₃(Al,Si,Rb)₄O₁₀(F,OH)₂).

Mineral