Rock Identifier

Category

Organic Structure (Not A Rock)

Browse organic structure (not a rock) specimens identified by the Rock Identifier community.

Banded Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Banded Chert

Microcrystalline Quartz (SiO2)

sedimentary
Granodiorite (Granodiorite (intermediate plutonic rock)) — igneous

Granodiorite

Granodiorite (intermediate plutonic rock)

igneous
Jasper (Jasper (Silicon Dioxide, SiO2)) — sedimentary

Jasper

Jasper (Silicon Dioxide, SiO2)

sedimentary
Sandstone (Pebble/Conglomerate fragment) (Sandstone (clastic sedimentary rock)) — Sedimentary Rock

Sandstone (Pebble/Conglomerate fragment)

Sandstone (clastic sedimentary rock)

Sedimentary Rock
Jasper (likely Brown or Brecciated) (Jasper (Silicon Dioxide, SiO2)) — sedimentary

Jasper (likely Brown or Brecciated)

Jasper (Silicon Dioxide, SiO2)

sedimentary
Granite (Granite (a plutonic igneous rock)) — Igneous

Granite

Granite (a plutonic igneous rock)

Igneous
Amethyst (Silicon Dioxide (SiO2) with Fe3+ impurities) — mineral

Amethyst

Silicon Dioxide (SiO2) with Fe3+ impurities

mineral
Banded Chert (Cryptocrystalline Quartz (SiO2)) — sedimentary

Banded Chert

Cryptocrystalline Quartz (SiO2)

sedimentary
Pumice (Pumice (Volcanic glass with vesicular texture)) — igneous

Pumice

Pumice (Volcanic glass with vesicular texture)

igneous
Mexican Crazy Lace Agate (Silicon Dioxide (SiO2) with iron and aluminum inclusions) — mineral

Mexican Crazy Lace Agate

Silicon Dioxide (SiO2) with iron and aluminum inclusions

mineral
Gastropod Fossil (Internal Mold) (Phylum Mollusca, Class Gastropoda (Steinkern)) — sedimentary

Gastropod Fossil (Internal Mold)

Phylum Mollusca, Class Gastropoda (Steinkern)

sedimentary
Quartzite (Quartzite (primarily SiO₂)) — metamorphic

Quartzite

Quartzite (primarily SiO₂)

metamorphic
Petrified Wood (Silicified Wood (SiO2 - Silicon Dioxide)) — mineral

Petrified Wood

Silicified Wood (SiO2 - Silicon Dioxide)

mineral
Quartzite with Hematite staining (Quartzite (SiO2)) — metamorphic

Quartzite with Hematite staining

Quartzite (SiO2)

metamorphic
Red Jasper (Silicon dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions) — sedimentary

Red Jasper

Silicon dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

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

Petrified Wood (Silicified Wood)

Silicified Wood (primarily Chalcedony/Quartz, SiO2)

mineral
Quartz Geode (Silicon Dioxide (SiO2) in Geode form) — sedimentary

Quartz Geode

Silicon Dioxide (SiO2) in Geode form

sedimentary
Quartz vein in metamorphic rock (Crystalline Silicon Dioxide (SiO2) in Host Rock) — metamorphic

Quartz vein in metamorphic rock

Crystalline Silicon Dioxide (SiO2) in Host Rock

metamorphic
Chert (specifically Jasper or Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Jasper or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

sedimentary
Sandstone (likely a river or beach pebble) (Sandstone (a clastic sedimentary rock)) — Sedimentary Rock

Sandstone (likely a river or beach pebble)

Sandstone (a clastic sedimentary rock)

Sedimentary Rock
Quartzite (Metamorphosed Quartz Sandstone (SiO2)) — metamorphic

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

metamorphic
Chert (Nodular) (Microcrystalline Silica (SiO2)) — sedimentary

Chert (Nodular)

Microcrystalline Silica (SiO2)

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

Anthracite Coal

Anthracite (Carbon-rich metamorphic rock)

metamorphic
Desert Rose (Gypsum (variety Selenite) - CaSO4·2H2O) — mineral

Desert Rose

Gypsum (variety Selenite) - CaSO4·2H2O

mineral
Gastropod Steinkern (Fossilized Snail Cast) (Phylum Mollusca, Class Gastropoda (Commonly CaCO3 or SiO2 after replacement)) — Sedimentary

Gastropod Steinkern (Fossilized Snail Cast)

Phylum Mollusca, Class Gastropoda (Commonly CaCO3 or SiO2 after replacement)

Sedimentary
Granite (Pink/Red Orthoclase variety) (Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8)) — igneous

Granite (Pink/Red Orthoclase variety)

Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8)

igneous
Chalcedony on Matrix (Silicon Dioxide (SiO2)) — mineral

Chalcedony on Matrix

Silicon Dioxide (SiO2)

mineral
Stiped Slate Beach Pebble (Low-grade Metamorphic Slate with Quartz Vein (SiO2 on Phyllosilicate base)) — metamorphic

Stiped Slate Beach Pebble

Low-grade Metamorphic Slate with Quartz Vein (SiO2 on Phyllosilicate base)

metamorphic
Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

sedimentary
Snowflake Obsidian (Spherulitic Volcanic Glass (SiO2 + impurities)) — igneous

Snowflake Obsidian

Spherulitic Volcanic Glass (SiO2 + impurities)

igneous
Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

metamorphic
Amber (Succinite (specifically for Baltic amber); C10H16O (Variable organic compound)) — mineral

Amber

Succinite (specifically for Baltic amber); C10H16O (Variable organic compound)

mineral
Quartz Geode (Silicon Dioxide (SiO2)) — mineral

Quartz Geode

Silicon Dioxide (SiO2)

mineral
Sandstone (Arenite (SiO2 based with various cements)) — sedimentary

Sandstone

Arenite (SiO2 based with various cements)

sedimentary
Moss Agate (Chalcedony (Silicon Dioxide with inclusions) - SiO2) — mineral

Moss Agate

Chalcedony (Silicon Dioxide with inclusions) - SiO2

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

Amethyst

Amethyst (Silicon Dioxide - SiO2 with iron impurities)

mineral
Herkimer Diamond in Matrix (Quartz (SiO2) in Dolostone (CaMg(CO3)2)) — sedimentary (host) / mineral (crystals)

Herkimer Diamond in Matrix

Quartz (SiO2) in Dolostone (CaMg(CO3)2)

sedimentary (host) / mineral (crystals)
Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

sedimentary
Note regarding image quality — Indeterminate

Note regarding image quality

Indeterminate
Conglomerate (Conglomerate (a clastic sedimentary rock)) — Sedimentary

Conglomerate

Conglomerate (a clastic sedimentary rock)

Sedimentary
Quartz Vein in Host Rock (Pebble) (Quartz (SiO2) with sandstone or siltstone matrix) — metamorphic/igneous transition

Quartz Vein in Host Rock (Pebble)

Quartz (SiO2) with sandstone or siltstone matrix

metamorphic/igneous transition
Red Jasper (Red Jasper (variety of Chalcedony, SiO₂)) — Mineral

Red Jasper

Red Jasper (variety of Chalcedony, SiO₂)

Mineral