Rock Identifier

Category

Mineraloid (Human Made Geological Specimen)

Browse mineraloid (human made geological specimen) specimens identified by the Rock Identifier community.

Polished/tumbled brown jasper or iron-rich chert (Microcrystalline quartz (SiO₂), commonly colored by hematite/goethite) — mineral

Polished/tumbled brown jasper or iron-rich chert

Microcrystalline quartz (SiO₂), commonly colored by hematite/goethite

Quartzite (Metamorphic Quartzite (SiO2)) — metamorphic

Quartzite

Metamorphic Quartzite (SiO2)

Chert (specifically Tan/Gray Chert) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (specifically Tan/Gray Chert)

Microcrystalline quartz (SiO2)

White Opal (Common) (Hydrated Silica (SiO2·nH2O)) — mineral

White Opal (Common)

Hydrated Silica (SiO2·nH2O)

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

Chert / Flint

Silicon Dioxide (SiO₂)

Chert (Jasper variety) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Chert (specifically Flint or Gray Chert) (Silicon Dioxide (SiO2)) — sedimentary

Chert (specifically Flint or Gray Chert)

Silicon Dioxide (SiO2)

Chert Nodule (Microcrystalline Quartz (SiO2)) — sedimentary

Chert Nodule

Microcrystalline Quartz (SiO2)

Obsidian (Volcanic Glass (SiO2)) — igneous

Obsidian

Volcanic Glass (SiO2)

Banded Chert / Chalcedony (Silicon Dioxide (SiO2)) — sedimentary

Banded Chert / Chalcedony

Silicon Dioxide (SiO2)

Chert Arrowhead (Projectile Point) (Microcrystalline Quartz (Chert/Flint)) — sedimentary

Chert Arrowhead (Projectile Point)

Microcrystalline Quartz (Chert/Flint)

Chert (Jasper variation) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper variation)

Silicon Dioxide (SiO2)

Common Opal with Host Rock (Opal (Hydrated silica, SiO2·nH2O)) — mineral

Common Opal with Host Rock

Opal (Hydrated silica, SiO2·nH2O)

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

Chert (Flint Arrowhead)

Microcrystalline Quartz (SiO2)

Jasper (Microcrystalline Quartz (Chalcedony), SiO2) — sedimentary

Jasper

Microcrystalline Quartz (Chalcedony), SiO2

Obsidian with Mahogany Phasing (Volcanic Glass (SiO2 + Fe2O3)) — igneous

Obsidian with Mahogany Phasing

Volcanic Glass (SiO2 + Fe2O3)

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

Brecciated Jasper

Brecciated Jasper (Microcrystalline Quartz / SiO2)

Blue Apatite (Fluorapatite (Ca5(PO4)3F)) — mineral

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Chert (Arrowhead) (Chert (SiO2)) — sedimentary

Chert (Arrowhead)

Chert (SiO2)

Blue Goldstone (Man-made glass with cobalt and metal flecks) — man-made glass

Blue Goldstone

Man-made glass with cobalt and metal flecks

Chert Pebble (Microcrystalline Quartz (SiO2)) — sedimentary

Chert Pebble

Microcrystalline Quartz (SiO2)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Chert (or Flint) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (or Flint)

Microcrystalline quartz (SiO2)

Goldstone (Brown/Gold) (Aventurine Glass (Man-made glass with Copper inclusions)) — gemstone

Goldstone (Brown/Gold)

Aventurine Glass (Man-made glass with Copper inclusions)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

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

Chert (Flinty variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Crackle Agate / Dyed Quartz (SiO2 (Silicon Dioxide)) — mineral

Crackle Agate / Dyed Quartz

SiO2 (Silicon Dioxide)

Obsidian (specifically Mahogany Obsidian) (Volcanic glass (high silica content, SiO2)) — igneous

Obsidian (specifically Mahogany Obsidian)

Volcanic glass (high silica content, SiO2)

Granite Pebble (Phaneritic plutonic rock (SiO2 primary)) — igneous

Granite Pebble

Phaneritic plutonic rock (SiO2 primary)

Brain Coral Fossil (Family Mussidae or Merulinidae (Order Scleractinia)) — sedimentary

Brain Coral Fossil

Family Mussidae or Merulinidae (Order Scleractinia)

Tumbled quartz-rich stone, possibly blue quartz or granite (Quartz (SiO₂), with probable feldspar and dark accessory minerals) — mineral

Tumbled quartz-rich stone, possibly blue quartz or granite

Quartz (SiO₂), with probable feldspar and dark accessory minerals

Slag (Metallurgical Slag) — igneous

Slag

Metallurgical Slag

Quartz Heart or Arrowhead Shape (Silicon Dioxide (SiO2)) — mineral

Quartz Heart or Arrowhead Shape

Silicon Dioxide (SiO2)

Obsidian (Volcanic Glass (SiO2)) — igneous

Obsidian

Volcanic Glass (SiO2)

Flint / Chert Pebble (Microcrystalline quartz (SiO2)) — sedimentary

Flint / Chert Pebble

Microcrystalline quartz (SiO2)

Obsidian (Obsidian (volcanic glass; primarily SiO2)) — igneous

Obsidian

Obsidian (volcanic glass; primarily SiO2)

Chert (or potentially Jasper/Chalcedony) (SiO2 (Silicon Dioxide)) — sedimentary

Chert (or potentially Jasper/Chalcedony)

SiO2 (Silicon Dioxide)

Mica Schist (Mica Schist (principally Biotite/Muscovite, Quartz, and Feldspar)) — metamorphic

Mica Schist

Mica Schist (principally Biotite/Muscovite, Quartz, and Feldspar)

Slag (Industrial Byproduct) (Artificial silicate/iron byproduct) — Mineral description (Anthropogenic material)

Slag (Industrial Byproduct)

Artificial silicate/iron byproduct

Mineral description (Anthropogenic material)

Black Obsidian (Obsidian (Volcanic Glass)) — igneous

Black Obsidian

Obsidian (Volcanic Glass)

Yellow Chert (Chalcedony) (Microcrystalline Quartz (SiO2)) — sedimentary

Yellow Chert (Chalcedony)

Microcrystalline Quartz (SiO2)