Rock Identifier

Category

Synthetic Or Natural Fiber

Browse synthetic or natural fiber specimens identified by the Rock Identifier community.

Rough Emerald in Matrix (Beryl (Be3Al2Si6O18) with trace Chromium/Vanadium) — mineral

Rough Emerald in Matrix

Beryl (Be3Al2Si6O18) with trace Chromium/Vanadium

Obsidian (Obsidian (principally SiO2 + MgO, Fe3O4)) — igneous

Obsidian

Obsidian (principally SiO2 + MgO, Fe3O4)

Magnetite Orthorthotropic Rock (Magnetite (Fe3O4)) — mineral

Magnetite Orthorthotropic Rock

Magnetite (Fe3O4)

Sandstone (Arenite (SiO2 primarily)) — sedimentary

Sandstone

Arenite (SiO2 primarily)

Black Spinel (Magnesium Aluminum Oxide (MgAl2O4)) — mineral

Black Spinel

Magnesium Aluminum Oxide (MgAl2O4)

Pumice (Extrusive volcanic rock (Vesicular Rhyolite/Dacite/Andesite)) — igneous

Pumice

Extrusive volcanic rock (Vesicular Rhyolite/Dacite/Andesite)

Smoky Quartz (Silicon Dioxide (SiO₂)) — mineral

Smoky Quartz

Silicon Dioxide (SiO₂)

Pearl (Aragonite (CaCO3 with conchiolin)) — mineral

Pearl

Aragonite (CaCO3 with conchiolin)

Ironstone Concretion (Pot Stone) (Siderite or Limonite Concretion (FeCO3 or FeO(OH)·nH2O)) — sedimentary

Ironstone Concretion (Pot Stone)

Siderite or Limonite Concretion (FeCO3 or FeO(OH)·nH2O)

Shale (or Mudstone) (Siltstone/Argillite (composed mainly of clay and silt-sized particles)) — sedimentary

Shale (or Mudstone)

Siltstone/Argillite (composed mainly of clay and silt-sized particles)

Sandstone (Ferruginous) (Arenite (composed primarily of SiO2 with Fe2O3 staining)) — sedimentary

Sandstone (Ferruginous)

Arenite (composed primarily of SiO2 with Fe2O3 staining)

Bumblebee Jasper (Volcanic Tuff (mixture of Quartz, Sulfur, Hematite, and Orpiment)) — igneous

Bumblebee Jasper

Volcanic Tuff (mixture of Quartz, Sulfur, Hematite, and Orpiment)

Pearl (Organic Mineraloid (CaCO3 + Conchiolin)) — mineral

Pearl

Organic Mineraloid (CaCO3 + Conchiolin)

Chert (often colloquially called Flint) (Chert (Microcrystalline Quartz, SiO2)) — sedimentary

Chert (often colloquially called Flint)

Chert (Microcrystalline Quartz, SiO2)

Black Freshwater Pearls (Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3) — mineral

Black Freshwater Pearls

Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3

Sandstone (Quartzose) (Arenite (composed mainly of SiO2)) — sedimentary

Sandstone (Quartzose)

Arenite (composed mainly of SiO2)

Herkimer Diamond (Quartz (Silicon Dioxide, SiO2)) — mineral

Herkimer Diamond

Quartz (Silicon Dioxide, SiO2)

Tektite (Indochinite) (Tektite (Silica-rich natural glass)) — mineral

Tektite (Indochinite)

Tektite (Silica-rich natural glass)

Pink Tumbled Quartz (Dyed) (Silicon Dioxide (SiO2)) — mineral

Pink Tumbled Quartz (Dyed)

Silicon Dioxide (SiO2)

Smoky Quartz (Silicon Dioxide (SiO2)) — mineral

Smoky Quartz

Silicon Dioxide (SiO2)

Sandstone (Ferruginous) (Arenite (Fe-rich SiO2)) — sedimentary

Sandstone (Ferruginous)

Arenite (Fe-rich SiO2)

Amethyst (Silicon Dioxide (SiO2) with trace Iron (Fe)) — mineral

Amethyst

Silicon Dioxide (SiO2) with trace Iron (Fe)

Orange Calcite (Calcite (Calcium Carbonate, CaCO3)) — mineral

Orange Calcite

Calcite (Calcium Carbonate, CaCO3)

Howlite (Howlite (Calcium borosilicate hydroxide, Ca2B5SiO9(OH)5)) — mineral

Howlite

Howlite (Calcium borosilicate hydroxide, Ca2B5SiO9(OH)5)

Shale (Lutaceous sedimentary rock) — sedimentary

Shale

Lutaceous sedimentary rock

Green Aventurine (Silicon Dioxide (SiO2) with Fuchsite inclusions) — metamorphic

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Obsidian (Volcanic Glass (Amorphous SiO2)) — igneous

Obsidian

Volcanic Glass (Amorphous SiO2)

Sandstone (Quartzose) (Arenite (SiO2 based)) — sedimentary

Sandstone (Quartzose)

Arenite (SiO2 based)

Green Aventurine (Silicon Dioxide (SiO2) with Fuchsite inclusions) — Mineral (Variety of Quartz)

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Mineral (Variety of Quartz)

Green Aventurine (Silicon Dioxide (SiO2) with Fuchsite inclusions) — metamorphic

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Ambergris (Ambra grisea (Metabolic byproduct)) — Organic (Geological relative)

Ambergris

Ambra grisea (Metabolic byproduct)

Organic (Geological relative)

Granite (Phaneritic Igneous Rock (Granitic)) — igneous

Granite

Phaneritic Igneous Rock (Granitic)

Red Granite (Felsic intrusive igneous rock (K-feldspar rich Granite)) — igneous

Red Granite

Felsic intrusive igneous rock (K-feldspar rich Granite)

Green Aventurine (Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)) — metamorphic

Green Aventurine

Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)

Moonstone (Feldspar variety) (Orthoclase Feldspar (KAlSi3O8)) — mineral

Moonstone (Feldspar variety)

Orthoclase Feldspar (KAlSi3O8)

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

Smoky Quartz (Tumbled)

Silicon Dioxide (SiO2)

Banded Gneiss (Gneiss (High-grade regional metamorphic rock)) — metamorphic

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Amethyst (Amethyst (Silica mineral, SiO2)) — mineral

Amethyst

Amethyst (Silica mineral, SiO2)

Amethyst (Amethyst (Silicon Dioxide with iron impurities), SiO2) — mineral

Amethyst

Amethyst (Silicon Dioxide with iron impurities), SiO2

Agate (Silicon Dioxide (SiO2)) — mineral

Agate

Silicon Dioxide (SiO2)

Granite (Granite (Phaneritic Acid Igneous Rock)) — igneous

Granite

Granite (Phaneritic Acid Igneous Rock)

Emerald In Matrix (Beryl (Be3Al2Si6O18) with trace Chromium/Vanadium) — mineral

Emerald In Matrix

Beryl (Be3Al2Si6O18) with trace Chromium/Vanadium