Rock Identifier

Category

Organic Crystal (Mineraloid)

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

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

Chert (Gravel)

Silicon Dioxide (SiO2)

Petrified Wood (Silicified Wood) (Silicified fossil wood (SiO2)) — metamorphic

Petrified Wood (Silicified Wood)

Silicified fossil wood (SiO2)

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

Chert (Jasper type)

Microcrystalline Quartz (SiO2)

Chert (variations include Flint) (Chert (Silicon Dioxide, SiO2)) — sedimentary

Chert (variations include Flint)

Chert (Silicon Dioxide, SiO2)

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

Dendritic Limestone (Calcite with Manganese Oxide (Manganese Dendrites)) — sedimentary

Dendritic Limestone

Calcite with Manganese Oxide (Manganese Dendrites)

Green Moss Agate (Silicon Dioxide with inclusions (SiO2 + Mn/Fe)) — sedimentary

Green Moss Agate

Silicon Dioxide with inclusions (SiO2 + Mn/Fe)

Slag Glass (Cullet) (Amorphous Silica (man-made), primarily SiO2 with trace metal oxides) — Mineraloid / Synthetic Glass

Slag Glass (Cullet)

Amorphous Silica (man-made), primarily SiO2 with trace metal oxides

Mineraloid / Synthetic Glass

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

Black Freshwater Pearls

Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3

Chert (Yellow/Brown variety) (Chert (SiO2)) — sedimentary

Chert (Yellow/Brown variety)

Chert (SiO2)

Chert (Yellow Jasper variant) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Yellow Jasper variant)

Microcrystalline Quartz (SiO2)

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

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Green Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Green Chert

Microcrystalline Quartz (SiO2)

Mother of Pearl (Nacre) (Nacre (Aragonite/Conchiolin), CaCO3 + Organic Polymers) — mineral

Mother of Pearl (Nacre)

Nacre (Aragonite/Conchiolin), CaCO3 + Organic Polymers

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

Chert (Iron-stained)

Microcrystalline quartz (SiO2)

Tektite (Indochinite) (Tektite (High-silica natural glass)) — mineraloid / impact glass

Tektite (Indochinite)

Tektite (High-silica natural glass)

mineraloid / impact glass

Anthracite Coal (Anthracite (Carbon-rich metamorphic coal)) — sedimentary

Anthracite Coal

Anthracite (Carbon-rich metamorphic coal)

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

Chert (and Flint variant)

Microcrystalline Quartz (SiO2)

Chert with Quartz Veining (Silicon Dioxide (SiO2)) — sedimentary

Chert with Quartz Veining

Silicon Dioxide (SiO2)

Chert (Beach Pebble) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Beach Pebble)

Microcrystalline Quartz (SiO2)

Chert (specifically as a lithic artifact/projectile point) (Chert (Silicon dioxide, SiO2)) — sedimentary

Chert (specifically as a lithic artifact/projectile point)

Chert (Silicon dioxide, SiO2)

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

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (Yellow Jasper variant) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Yellow Jasper variant)

Silicon Dioxide (SiO2)

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

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Red Moss Agate (Jasper) (Silicon Dioxide (SiO2) with Iron Oxide inclusions) — sedimentary

Red Moss Agate (Jasper)

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Tree Agate (Silicon Dioxide (SiO2) with Dendritic Inclusions) — Mineral

Tree Agate

Silicon Dioxide (SiO2) with Dendritic Inclusions

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

Pyrite in Shale (Iron Sulfide (FeS2) in Sedimentary Matrix) — mineral

Pyrite in Shale

Iron Sulfide (FeS2) in Sedimentary Matrix

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

Chert (Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (often called Flint) (Chert (SiO2)) — sedimentary

Chert (often called Flint)

Chert (SiO2)

Chert (often called Jasper or River Siltstone) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (often called Jasper or River Siltstone)

Microcrystalline Quartz (SiO2)

Green Moss Agate (Silicon Dioxide with inclusions (SiO2)) — sedimentary

Green Moss Agate

Silicon Dioxide with inclusions (SiO2)

Synthetic Resin (Artificial Specimen) (Polyurethane or Polyester Resin) — mineraloid (man-made)

Synthetic Resin (Artificial Specimen)

Polyurethane or Polyester Resin

mineraloid (man-made)

Tektite (specifically Indochinite) (Tektite (Natural silica glass)) — Mineraloid (Impact glass)

Tektite (specifically Indochinite)

Tektite (Natural silica glass)

Mineraloid (Impact glass)

Chert (often found as Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often found as Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Moss Agate (Silicon Dioxide (SiO2) with mineral inclusions) — Mineral

Moss Agate

Silicon Dioxide (SiO2) with mineral inclusions

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

Chert (River Pebble)

Microcrystalline Quartz (SiO2)

Moss Agate / Chalcedony (Silicon Dioxide (SiO2)) — mineral

Moss Agate / Chalcedony

Silicon Dioxide (SiO2)

Chert (Jasper-bearing) (Microcrystalline silica (SiO2) with iron oxide inclusions) — sedimentary

Chert (Jasper-bearing)

Microcrystalline silica (SiO2) with iron oxide inclusions

Petrified Wood (Silicified Wood (primarily Chalcedony or Quartz, SiO2)) — sedimentary

Petrified Wood

Silicified Wood (primarily Chalcedony or Quartz, SiO2)

Petrified Wood (Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)) — mineral

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)

Chert (often called Flint or Agate nodule) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint or Agate nodule)

Cryptocrystalline Quartz (SiO2)