Rock Identifier

Category

Organic Crystal (Mineraloid)

Browse organic crystal (mineraloid) specimens identified by the Rock Identifier community.

Fossilized Horn Coral (Order Rugosa (Rugose Coral)) — sedimentary

Fossilized Horn Coral

Order Rugosa (Rugose Coral)

Jasper (Silicon dioxide (SiO2)) — sedimentary

Jasper

Silicon dioxide (SiO2)

Chert (with Limonite staining) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (with Limonite staining)

Microcrystalline Quartz (SiO2)

Dinosaur Fossil (Skull) (Dinosauria fossilis (Petrified Hydroxyapatite / Calcium Carbonate)) — sedimentary

Dinosaur Fossil (Skull)

Dinosauria fossilis (Petrified Hydroxyapatite / Calcium Carbonate)

Chert (and its variety Flint) (Silicon dioxide (SiO2) / Microcrystalline quartz) — sedimentary

Chert (and its variety Flint)

Silicon dioxide (SiO2) / Microcrystalline quartz

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

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically Flint) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Flint)

Cryptocrystalline Quartz (SiO2)

Chert (Iron-stained) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Chert (Iron-stained) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Iron-stained)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Moss Agate (Chalcedony (SiO2) with inclusions of manganese or iron oxide) — mineral

Moss Agate

Chalcedony (SiO2) with inclusions of manganese or iron oxide

Mookaite Jasper (Silicified Radiolarite (SiO2 with iron impurities)) — sedimentary

Mookaite Jasper

Silicified Radiolarite (SiO2 with iron impurities)

Chert (specifically Pink Chert or Jasperized Chert) (Silicon Dioxide (SiO2) - Cryptocrystalline Quartz) — sedimentary

Chert (specifically Pink Chert or Jasperized Chert)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Chert (specifically Red Chert / Jasper) (Silicon Dioxide (SiO2)) — sedimentary

Chert (specifically Red Chert / Jasper)

Silicon Dioxide (SiO2)

Chert (Iron-rich variety) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Iron-rich variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert Nodule (Flint)

Microcrystalline Quartz (SiO2)

Black Jasper (Silicon Dioxide (SiO2) with inclusions) — sedimentary

Black Jasper

Silicon Dioxide (SiO2) with inclusions

Pyrite in Shaly Matrix (Iron Sulfide (FeS2)) — mineral

Pyrite in Shaly Matrix

Iron Sulfide (FeS2)

Chalcedony (Botryoidal or Tumbled) (Chalcedony (SiO₂)) — mineral

Chalcedony (Botryoidal or Tumbled)

Chalcedony (SiO₂)

Coral Rock (Coquina) (Biogenic Limestone (Calcium Carbonate - CaCO3)) — sedimentary

Coral Rock (Coquina)

Biogenic Limestone (Calcium Carbonate - CaCO3)

Chert (Yellow or Tan Chert) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Yellow or Tan Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Black Jasper (Black Jasper (Silicate mineral - SiO2)) — sedimentary

Black Jasper

Black Jasper (Silicate mineral - SiO2)

Chert (often called Flint or River Stone) (Chert (SiO2)) — sedimentary

Chert (often called Flint or River Stone)

Chert (SiO2)

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

Agatized Fossil (Druzy Agate)

Silicon Dioxide (SiO2) replacing organic matter

Chert (Flint nodule) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert (Flint nodule)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (Light Grey / Flint variant) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Light Grey / Flint variant)

Cryptocrystalline Quartz (SiO2)

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

Chert (Gravel)

Microcrystalline Quartz (SiO2)

Moss Agate (Silicon Dioxide with inclusions (SiO2 + Fe/Mn/Mg)) — mineral

Moss Agate

Silicon Dioxide with inclusions (SiO2 + Fe/Mn/Mg)

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

Chert (Flint)

Microcrystalline Silica (SiO2)

Geode (Unopened) (Silica-rich concretion (SiO2)) — sedimentary

Geode (Unopened)

Silica-rich concretion (SiO2)

Chert (Nodule) (Chert (composition: SiO2)) — sedimentary

Chert (Nodule)

Chert (composition: SiO2)

Chert (and Petrified Wood) (Silicon Dioxide (SiO2)) — sedimentary

Chert (and Petrified Wood)

Silicon Dioxide (SiO2)

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

Jasper with Agate and Quartz Inclusions (Silicon Dioxide (SiO2) - Chalcedony / Quartz aggregate) — sedimentary

Jasper with Agate and Quartz Inclusions

Silicon Dioxide (SiO2) - Chalcedony / Quartz aggregate

Chert (often called Flint or River Pebble) (Chert (Microcrystalline Quartz, SiO2)) — sedimentary

Chert (often called Flint or River Pebble)

Chert (Microcrystalline Quartz, SiO2)

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

Banded Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (Nodule) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert (Cherty Shale / Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (White-Grey variety) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (White-Grey variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Glauconitic Sandstone (Greenstone) (Glauconitic Siliciclastic Sandstone (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2) — sedimentary

Glauconitic Sandstone (Greenstone)

Glauconitic Siliciclastic Sandstone (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2

River Pebble (Siltstone/Mudstone) (Clastic sedimentary rock) — sedimentary

River Pebble (Siltstone/Mudstone)

Clastic sedimentary rock

Pyrite in Limestone (Iron Sulfide (FeS2) in Calcium Carbonate (CaCO3)) — mineral

Pyrite in Limestone

Iron Sulfide (FeS2) in Calcium Carbonate (CaCO3)

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

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)