Rock Identifier

Category

Organic (Non Geological)

Browse organic (non geological) specimens identified by the Rock Identifier community.

Chrysanthemum Stone (Celestine (SrSO4) or Calcite (CaCO3) in Limestone/Porphyry matrix) — metamorphic

Chrysanthemum Stone

Celestine (SrSO4) or Calcite (CaCO3) in Limestone/Porphyry matrix

Chert / Jasper (Microcrystalline Quartz (SiO2)) — sedimentary

Chert / Jasper

Microcrystalline Quartz (SiO2)

Chert (Jasper variety) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper variety)

Cryptocrystalline Quartz (SiO2)

Chert (with Limestone matrix) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (with Limestone matrix)

Microcrystalline Quartz (SiO2)

Chert (Red Jasper) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Red Jasper)

Microcrystalline Quartz (SiO2)

Chert (Jasper/Flint variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Obsidian Arrowhead (Obsidian (volcanic glass, SiO2 rich)) — igneous

Obsidian Arrowhead

Obsidian (volcanic glass, SiO2 rich)

Travertine (Travertine (a terrestrial form of Limestone, CaCO3)) — sedimentary

Travertine

Travertine (a terrestrial form of Limestone, CaCO3)

Anthracite Coal (Anthracite (Carbon-based organic sedimentary rock exposed to metamorphic heat/pressure; Chemical composition is approximately 86%–98% Carbon)) — metamorphic

Anthracite Coal

Anthracite (Carbon-based organic sedimentary rock exposed to metamorphic heat/pressure; Chemical composition is approximately 86%–98% Carbon)

Obsidian (Volcanic glass (primary composition: SiO2)) — igneous

Obsidian

Volcanic glass (primary composition: SiO2)

Chert / Flint (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert / Flint

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Obsidian (Amorphous volcanic glass (70-75% SiO2)) — igneous

Obsidian

Amorphous volcanic glass (70-75% SiO2)

Polished brecciated jasper (Silicified microcrystalline quartz (SiO₂), commonly called brecciated or ocean jasper) — metamorphic

Polished brecciated jasper

Silicified microcrystalline quartz (SiO₂), commonly called brecciated or ocean jasper

Petrified Wood (Silicified Wood (primarily SiO2)) — sedimentary

Petrified Wood

Silicified Wood (primarily SiO2)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Weathered agate or chalcedony nodule (Microcrystalline quartz (SiO₂), likely agate/chalcedony with iron-oxide staining) — mineral

Weathered agate or chalcedony nodule

Microcrystalline quartz (SiO₂), likely agate/chalcedony with iron-oxide staining

Quartz-rich metamorphic pebble (Milky quartz with possible feldspar and mica; likely quartzite or quartz-veined metamorphic rock) — metamorphic

Quartz-rich metamorphic pebble

Milky quartz with possible feldspar and mica; likely quartzite or quartz-veined metamorphic rock

Agatized Fossil (Druzy Agate) (Silicon Dioxide (SiO2) replacing organic matter) — sedimentary

Agatized Fossil (Druzy Agate)

Silicon Dioxide (SiO2) replacing organic matter

Black Tourmaline (Schorl) (Sodium Iron Aluminum Borosilicate (NaFe2+3Al6(BO3)3Si6O18(OH)4)) — mineral

Black Tourmaline (Schorl)

Sodium Iron Aluminum Borosilicate (NaFe2+3Al6(BO3)3Si6O18(OH)4)

Quartzite (Quartzite (chiefly SiO2)) — metamorphic

Quartzite

Quartzite (chiefly SiO2)

Obsidian (Volcanic glass (SiO2 + impurities)) — igneous

Obsidian

Volcanic glass (SiO2 + impurities)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Obsidian (Volcanic Glass (SiO2 + impurities)) — igneous

Obsidian

Volcanic Glass (SiO2 + impurities)

Chert with Fossil Brachiopod (Microcrystalline Quartz (SiO2) with Calcitic Brachiopod inclusion) — sedimentary

Chert with Fossil Brachiopod

Microcrystalline Quartz (SiO2) with Calcitic Brachiopod inclusion

Black Obsidian (Obsidian (Volcanic glass), 70–75% SiO2) — igneous

Black Obsidian

Obsidian (Volcanic glass), 70–75% SiO2

Petrified Wood (Silicified Wood (primarily SiO2)) — fossil

Petrified Wood

Silicified Wood (primarily SiO2)

Obsidian (Volcanic Glass) — igneous

Obsidian

Volcanic Glass

Limestone with Chert Nodule (Carbonate rock (CaCO3) with Microcrystalline Silicon Dioxide (SiO2) inclusion) — sedimentary

Limestone with Chert Nodule

Carbonate rock (CaCO3) with Microcrystalline Silicon Dioxide (SiO2) inclusion

Obsidian Arrowhead (Volcanic Glass (predominantly SiO2)) — igneous

Obsidian Arrowhead

Volcanic Glass (predominantly SiO2)

Obsidian (Volcanic Glass (Amorphous SiO2-rich glass)) — Igneous

Obsidian

Volcanic Glass (Amorphous SiO2-rich glass)

Black Obsidian (Obsidian (Volcanic Glass)) — igneous

Black Obsidian

Obsidian (Volcanic Glass)

Rounded river pebble, likely basalt or andesite (Fine-grained mafic to intermediate volcanic rock; exact identification requires testing) — igneous

Rounded river pebble, likely basalt or andesite

Fine-grained mafic to intermediate volcanic rock; exact identification requires testing

Black Obsidian (Obsidian (Volcanic Glass, ~70% SiO2)) — igneous

Black Obsidian

Obsidian (Volcanic Glass, ~70% SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Banded Chert (River Pebble) (Microcrystalline Quartz (SiO2)) — sedimentary

Banded Chert (River Pebble)

Microcrystalline Quartz (SiO2)

Obsidian (Volcanic Glass (70% or more SiO2)) — igneous

Obsidian

Volcanic Glass (70% or more SiO2)

Anthracite Coal (Anthracite) — metamorphic

Anthracite Coal

Anthracite

Banded Sandstone (Liesegang Rings) (Sedimentary sandstone with Iron oxide precipitates) — sedimentary

Banded Sandstone (Liesegang Rings)

Sedimentary sandstone with Iron oxide precipitates

Blue Slag Glass (Man-made Silicon Dioxide (Amorphous)) — Anthropogenic (Man-made)

Blue Slag Glass

Man-made Silicon Dioxide (Amorphous)

Anthropogenic (Man-made)

Snowflake Obsidian (Spherulitic Volcanic Glass (primarily SiO2)) — igneous

Snowflake Obsidian

Spherulitic Volcanic Glass (primarily SiO2)

Likely bituminous coal (Coal, predominantly carbon-rich organic matter; exact rank cannot be confirmed from the image) — sedimentary

Likely bituminous coal

Coal, predominantly carbon-rich organic matter; exact rank cannot be confirmed from the image

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)