Rock Identifier

Category

Organic Crystal (Mineraloid)

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

Septarian Nodule (Septarian Concretion) — sedimentary

Septarian Nodule

Septarian Concretion

Petrified Wood (Silicified Wood (SiO2)) — mineral

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified wood (primarily quartz, SiO2)) — fossil

Petrified Wood

Silicified wood (primarily quartz, SiO2)

Petrified Wood (Silicified wood (Quartz / Chalcedonized wood, SiO2)) — sedimentary

Petrified Wood

Silicified wood (Quartz / Chalcedonized wood, SiO2)

Anthracite Coal (Anthracite (Metamorphic/High-grade Sedimentary Coal)) — sedimentary

Anthracite Coal

Anthracite (Metamorphic/High-grade Sedimentary Coal)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified Wood (primarily quartz/chalcedony replacing organic wood structures, SiO2)) — fossil

Petrified Wood

Silicified Wood (primarily quartz/chalcedony replacing organic wood structures, SiO2)

Septarian Nodule (Septarian Dragon Stone) (Septarian Concretion (Composition: Calcite, Aragonite, and Limestone/Clay)) — sedimentary

Septarian Nodule (Septarian Dragon Stone)

Septarian Concretion (Composition: Calcite, Aragonite, and Limestone/Clay)

Anthracite Coal (Anthracite (Carbon-based organic sedimentary rock transitioned to metamorphic)) — metamorphic

Anthracite Coal

Anthracite (Carbon-based organic sedimentary rock transitioned to metamorphic)

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

Petrified Wood

Silicified wood (primarily SiO2)

Unknown Organic Object (likely a berry or fruit) (Not applicable; this is not a geological specimen. If it were a cranberry, its scientific name would be Vaccinium macrocarpon; if a cherry, it would be Prunus avium or Prunus cerasus.) — Organic Material (likely a fruit or berry)

Unknown Organic Object (likely a berry or fruit)

Not applicable; this is not a geological specimen. If it were a cranberry, its scientific name would be Vaccinium macrocarpon; if a cherry, it would be Prunus avium or Prunus cerasus.

Organic Material (likely a fruit or berry)

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

Petrified Wood (Silicified Wood)

Silicified Wood (primarily Chalcedony/Quartz, SiO2)

Aventurine (likely Green Aventurine) (Silicon Dioxide (SiO2) with mineral inclusions) — Mineral/Mineraloid within a rock matrix

Aventurine (likely Green Aventurine)

Silicon Dioxide (SiO2) with mineral inclusions

Mineral/Mineraloid within a rock matrix

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Sea Glass (Frosted Glass) (Amorphous Silica (SiO2) with various additives) — Man-made material (Anthropogenic 'mineraloid')

Sea Glass (Frosted Glass)

Amorphous Silica (SiO2) with various additives

Man-made material (Anthropogenic 'mineraloid')

Graphite (Graphite (Carbon, C)) — Mineral

Graphite

Graphite (Carbon, C)

Petrified Wood (Silicified Wood (primarily quartz/chalcedony replacing organic wood structure, SiO2)) — sedimentary

Petrified Wood

Silicified Wood (primarily quartz/chalcedony replacing organic wood structure, SiO2)

Green Sea Glass (Amorphous Silica (man-made glass), SiO2 + additive metal oxides) — mineraloid / anthropogenic (man-made origin)

Green Sea Glass

Amorphous Silica (man-made glass), SiO2 + additive metal oxides

mineraloid / anthropogenic (man-made origin)

Black Marble with Quartz Veining (Metamorphosed Limestone (Recrystallized CaCO3)) — metamorphic

Black Marble with Quartz Veining

Metamorphosed Limestone (Recrystallized CaCO3)

Fossilized Wood (Petrified Wood) (Silicified Wood (primarily quartz/chalcedony replacing organic matter)) — Sedimentary (with some aspects of mineral replacement)

Fossilized Wood (Petrified Wood)

Silicified Wood (primarily quartz/chalcedony replacing organic matter)

Sedimentary (with some aspects of mineral replacement)

Chert (specifically a stream-worn Chert Nodule) (Sedimentary Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically a stream-worn Chert Nodule)

Sedimentary Cryptocrystalline Quartz (SiO2)

Sea Glass (specifically Frosted White) (Amorphous Silica (substance: Sodium-calcium silicate glass)) — Mineraloid (Anthropogenic/Man-made rock)

Sea Glass (specifically Frosted White)

Amorphous Silica (substance: Sodium-calcium silicate glass)

Mineraloid (Anthropogenic/Man-made rock)

Shale with Vein Infillings (Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.) — Sedimentary Rock

Shale with Vein Infillings

Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.

Sedimentary Rock

Red Jasper (beads) (SiO₂ (Silicon Dioxide)) — Mineral, variety of chalcedony (microcrystalline quartz)

Red Jasper (beads)

SiO₂ (Silicon Dioxide)

Mineral, variety of chalcedony (microcrystalline quartz)

Petrified Wood (Silicified wood (Quartz / Chalcedony replacement)) — fossil

Petrified Wood

Silicified wood (Quartz / Chalcedony replacement)

Baroque Pearl (Calcium Carbonate (Aragonite or Calcite) and Conchiolin) — Organic Gemstone

Baroque Pearl

Calcium Carbonate (Aragonite or Calcite) and Conchiolin

Organic Gemstone

Popcorn (Zea mays everta (P. Wilson) (Botanical name for the corn variety)) — Organic/Biogenic

Popcorn

Zea mays everta (P. Wilson) (Botanical name for the corn variety)

Organic/Biogenic

Mother of Pearl (Nacre) (Calcium Carbonate (primarily aragonite, with conchiolin)) — Organic Gemstone/Biomineral

Mother of Pearl (Nacre)

Calcium Carbonate (primarily aragonite, with conchiolin)

Organic Gemstone/Biomineral

Brown Jasper (Likely) (Jasper (Cryptocrystalline Silicon Dioxide - SiO2)) — Mineral

Brown Jasper (Likely)

Jasper (Cryptocrystalline Silicon Dioxide - SiO2)

Red Jasper (Red Jasper (variety of Chalcedony, SiO₂)) — Mineral

Red Jasper

Red Jasper (variety of Chalcedony, SiO₂)

Shale (Shale) — sedimentary

Shale

Shale

Amber (Copal) (Organic gemstone, fossilized tree resin (often immature amber or copal)) — Mineral

Amber (Copal)

Organic gemstone, fossilized tree resin (often immature amber or copal)

Amber ((C10H16O)n – an amorphous organic substance, primarily composed of polymerized isoprenoids.) — Mineral

Amber

(C10H16O)n – an amorphous organic substance, primarily composed of polymerized isoprenoids.

Petrified Wood (Silicified Wood / Fossilized Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood / Fossilized Wood (SiO2)

Amber (Fossilized Tree Resin (Amorphous Hydrocarbon)) — Mineral

Amber

Fossilized Tree Resin (Amorphous Hydrocarbon)

Wood Jasper (Siliceous sedimentary rock (variety of Chert/Chalcedony)) — Sedimentary

Wood Jasper

Siliceous sedimentary rock (variety of Chert/Chalcedony)

Chert / Flint (Chert (varietal name for microcrystalline quartz). Chemical formula: SiO₂) — Mineral

Chert / Flint

Chert (varietal name for microcrystalline quartz). Chemical formula: SiO₂

Pyrite (Pyrite (FeS2)) — Mineral

Pyrite

Pyrite (FeS2)

Conglomerate (Conglomerate) — Sedimentary Rock

Conglomerate

Conglomerate

Sedimentary Rock

Chert / Flint (Chert (varieties include Flint)) — Sedimentary

Chert / Flint

Chert (varieties include Flint)

Pyrite (Pyrite (Iron Disulfide), FeS2) — Mineral

Pyrite

Pyrite (Iron Disulfide), FeS2

Shale or Mudstone (Based on appearance) (Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)) — Sedimentary

Shale or Mudstone (Based on appearance)

Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)