Rock Identifier

Category

Sedimentary (Volcanic)

Browse sedimentary (volcanic) specimens identified by the Rock Identifier community.

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

Brown Jasper (Likely)

Jasper (Cryptocrystalline Silicon Dioxide - SiO2)

Larimar (Pectolite (a variety of pectolite, NaCa2Si3O8(OH))) — Mineral

Larimar

Pectolite (a variety of pectolite, NaCa2Si3O8(OH))

Obsidian (Obsidian (Volcanic Glass, ~70–75% SiO2)) — igneous

Obsidian

Obsidian (Volcanic Glass, ~70–75% SiO2)

Basalt (Polished River Stone) (Mafic Volcanic Rock (primarily Plagioclase and Pyroxene)) — Igneous

Basalt (Polished River Stone)

Mafic Volcanic Rock (primarily Plagioclase and Pyroxene)

Carnelian (Carnelian (a variety of Chalcedony, SiO2)) — Mineral

Carnelian

Carnelian (a variety of Chalcedony, SiO2)

Basalt (Water-worn Pebble) (Basalt (Aphanitic Mafic Igneous Rock)) — igneous

Basalt (Water-worn Pebble)

Basalt (Aphanitic Mafic Igneous Rock)

Limonite (Iron Stone Concretion) (Limonite (Hydrous Iron Oxide) - FeO(OH)·nH2O) — mineral

Limonite (Iron Stone Concretion)

Limonite (Hydrous Iron Oxide) - FeO(OH)·nH2O

Obsidian (Black Obsidian) (Amorphous volcanic glass (primarily SiO2)) — igneous

Obsidian (Black Obsidian)

Amorphous volcanic glass (primarily SiO2)

Mahogany Obsidian (Volcanic Glass (Silicate: SiO2 + Fe2O3)) — igneous

Mahogany Obsidian

Volcanic Glass (Silicate: SiO2 + Fe2O3)

Basalt (River Rock Cobble) (Extrusive mafic volcanic rock (Basalt)) — igneous

Basalt (River Rock Cobble)

Extrusive mafic volcanic rock (Basalt)

Obsidian (Volcanic glass (primary composition: SiO2)) — igneous

Obsidian

Volcanic glass (primary composition: SiO2)

Basalt (River Pebble) (Basalt (Aphanitic Mafic Volcanic Rock)) — igneous

Basalt (River Pebble)

Basalt (Aphanitic Mafic Volcanic Rock)

Mahogany Obsidian Arrowhead (Obsidian (volcanic glass) with Hematite inclusions) — igneous

Mahogany Obsidian Arrowhead

Obsidian (volcanic glass) with Hematite inclusions

Obsidian (Volcanic Glass (comprised primarily of SiO2)) — Igneous

Obsidian

Volcanic Glass (comprised primarily of SiO2)

Basalt (Basalt (containing Pyroxene, Plagioclase feldspar, and Olivine)) — igneous

Basalt

Basalt (containing Pyroxene, Plagioclase feldspar, and Olivine)

Basalt (Basalt (composition of plagioclase feldspar and pyroxene)) — igneous

Basalt

Basalt (composition of plagioclase feldspar and pyroxene)

Basalt (Mafic volcanic rock (Primary minerals: Plagioclase feldspar, Pyroxene)) — igneous

Basalt

Mafic volcanic rock (Primary minerals: Plagioclase feldspar, Pyroxene)

Silver (Native Element) (Ag (Argentum)) — mineral

Silver (Native Element)

Ag (Argentum)

Diorite (Salt and Pepper Rock) (Diorite) — igneous

Diorite (Salt and Pepper Rock)

Diorite

Diamond (or high-quality simulant like Cubic Zirconia) (Carbon (C) - Native Element) — mineral

Diamond (or high-quality simulant like Cubic Zirconia)

Carbon (C) - Native Element

Diorite (Diorite (Intermediate intrusive igneous rock)) — igneous

Diorite

Diorite (Intermediate intrusive igneous rock)

Diorite (Diorite (Intermediate intrusive igneous rock)) — igneous

Diorite

Diorite (Intermediate intrusive igneous rock)

Carnelian (Red Chalcedony) (Silicon Dioxide (SiO2)) — mineral

Carnelian (Red Chalcedony)

Silicon Dioxide (SiO2)

Prehnite (Prehnite (Ca2Al(AlSi3O10)(OH)2)) — mineral

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Blue Calcite (Calcium Carbonate (CaCO3)) — mineral

Blue Calcite

Calcium Carbonate (CaCO3)

Botryoidal Pyrite (Iron Sulfide (FeS2)) — mineral

Botryoidal Pyrite

Iron Sulfide (FeS2)

Garnet Rhyolite (Rhyolite (high-silica volcanic rock) with almandine/spessartine garnet) — igneous

Garnet Rhyolite

Rhyolite (high-silica volcanic rock) with almandine/spessartine garnet

Fossiliferous Limestone with Brachiopods (Calcium Carbonate (CaCO3) with fossilized Brachiopoda sp. (likely Order Spiriferida or Rhynchonellida)) — sedimentary

Fossiliferous Limestone with Brachiopods

Calcium Carbonate (CaCO3) with fossilized Brachiopoda sp. (likely Order Spiriferida or Rhynchonellida)

Agate (Silicon dioxide (SiO2)) — mineral

Agate

Silicon dioxide (SiO2)

Black Obsidian (Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide) with impurities) — igneous

Black Obsidian

Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide) with impurities

Agate (Silicon dioxide (SiO2) - variety Chalcedony) — mineral

Agate

Silicon dioxide (SiO2) - variety Chalcedony

Olivine (Peridot) (Magnesium Iron Silicate ((Mg, Fe)2SiO4)) — mineral

Olivine (Peridot)

Magnesium Iron Silicate ((Mg, Fe)2SiO4)

Rhyolite (Rhyolite) — igneous

Rhyolite

Rhyolite

Porphyritic Basalt (Porphyritic Basalt (with Plagioclase phenocrysts)) — igneous

Porphyritic Basalt

Porphyritic Basalt (with Plagioclase phenocrysts)

Agate Geode (Microcrystalline Quartz (SiO2)) — mineral

Agate Geode

Microcrystalline Quartz (SiO2)

Banded Agate (Silicon Dioxide (SiO2)) — mineral

Banded Agate

Silicon Dioxide (SiO2)

Basalt River Stone (Aphanitic Mafic Igneous Rock) — igneous

Basalt River Stone

Aphanitic Mafic Igneous Rock

Basalt (Extrusive mafic igneous rock) — igneous

Basalt

Extrusive mafic igneous rock

Greenstone with Quartz Veining (Epidiorite or Metabasalt with SiO2 (Quartz) veins) — metamorphic

Greenstone with Quartz Veining

Epidiorite or Metabasalt with SiO2 (Quartz) veins

Epidote in Matrix (Epidote; Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)) — metamorphic

Epidote in Matrix

Epidote; Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

Sunstone (Oligoclase (Plagioclase Feldspar), (Na,Ca)(Si,Al)4O8) — mineral

Sunstone

Oligoclase (Plagioclase Feldspar), (Na,Ca)(Si,Al)4O8

Basalt (with Plagioclase Phenocrysts) (Porphyritic Basalt) — igneous

Basalt (with Plagioclase Phenocrysts)

Porphyritic Basalt