Rock Identifier

Category

Organic (Geological Relative)

Browse organic (geological relative) specimens identified by the Rock Identifier community.

Coquina (Biogenic Limestone (Calcium Carbonate, CaCO3)) — sedimentary

Coquina

Biogenic Limestone (Calcium Carbonate, CaCO3)

Metallic Ornament / Jewelry (N/A - This is an artificial object, not a geological specimen.) — This appears to be a man-made metallic object, likely jewelry, not a natural rock, mineral, or geological specimen.

Metallic Ornament / Jewelry

N/A - This is an artificial object, not a geological specimen.

This appears to be a man-made metallic object, likely jewelry, not a natural rock, mineral, or geological specimen.

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

Black Obsidian

Obsidian (Amorphous volcanic glass, SiO2)

Black Obsidian (Volcanic Glass (SiO2 + impurities)) — igneous

Black Obsidian

Volcanic Glass (SiO2 + impurities)

Slate (Slate (Metamorphosed Shale or Mudstone)) — metamorphic

Slate

Slate (Metamorphosed Shale or Mudstone)

Quartz (Milky or White Quartz) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky or White Quartz)

Silicon Dioxide (SiO2)

Mixed collection of common river stones (Varied lithologies, visibly including quartz-rich rock, dark mafic rock, sandstone, and purple quartz-bearing material) — igneous, sedimentary, metamorphic

Mixed collection of common river stones

Varied lithologies, visibly including quartz-rich rock, dark mafic rock, sandstone, and purple quartz-bearing material

igneous, sedimentary, metamorphic

Slate (Foliated Metamorphic Rock (composed of quartz, illite, and chlorite)) — metamorphic

Slate

Foliated Metamorphic Rock (composed of quartz, illite, and chlorite)

Fossil Shark Tooth (Carcharodon carcharias (modern/recent) or similar Lamniform fossil) — fossil

Fossil Shark Tooth

Carcharodon carcharias (modern/recent) or similar Lamniform fossil

Slate (Slate (foliated metamorphic rock)) — metamorphic

Slate

Slate (foliated metamorphic rock)

Granite (Granite (composed primarily of Quartz SiO2, Alkali Feldspar, and Plagioclase Feldspar)) — igneous

Granite

Granite (composed primarily of Quartz SiO2, Alkali Feldspar, and Plagioclase Feldspar)

Quartz (Milky/Common variety) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky/Common variety)

Silicon Dioxide (SiO2)

Bumblebee Jasper (Fibrous Calcite and Quartz with Volcanic Matter (CaCO3 / SiO2)) — mineral

Bumblebee Jasper

Fibrous Calcite and Quartz with Volcanic Matter (CaCO3 / SiO2)

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

Obsidian

Amorphous volcanic glass (primarily SiO2)

Milky Quartz with Iron Inclusions (Quartz (Silicon Dioxide - SiO2)) — mineral

Milky Quartz with Iron Inclusions

Quartz (Silicon Dioxide - SiO2)

Honey Calcite (Calcium Carbonate (CaCO3)) — mineral

Honey Calcite

Calcium Carbonate (CaCO3)

Tumbled black stone, likely basalt or obsidian (Uncertain; likely fine-grained basalt (plagioclase–pyroxene) or dark volcanic glass (obsidian)) — igneous

Tumbled black stone, likely basalt or obsidian

Uncertain; likely fine-grained basalt (plagioclase–pyroxene) or dark volcanic glass (obsidian)

Milky Quartz (Quartz (SiO2)) — mineral

Milky Quartz

Quartz (SiO2)

Bumblebee Jasper (Calcite-bearing Volcanic Tuff containing Sulfur and Arsenic (Orpiment/Realgar)) — sedimentary

Bumblebee Jasper

Calcite-bearing Volcanic Tuff containing Sulfur and Arsenic (Orpiment/Realgar)

Granite (Intrusive Igneous Rock) — igneous

Granite

Intrusive Igneous Rock

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Black Obsidian (Obsidian (Amorphous Silicon Dioxide)) — igneous

Black Obsidian

Obsidian (Amorphous Silicon Dioxide)

Green Opal or Yellow Opal (Hydrated Silica (SiO2·nH2O)) — mineraloid

Green Opal or Yellow Opal

Hydrated Silica (SiO2·nH2O)

Granite (Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8)) — igneous

Granite

Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8)

Granite Pebble (Granite) — igneous

Granite Pebble

Granite

Obsidian (Obsidian (Volcanic Glass, primarily SiO2)) — igneous

Obsidian

Obsidian (Volcanic Glass, primarily SiO2)

Chalcedony (Agate/Chert variety) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Agate/Chert variety)

Silicon Dioxide (SiO2)

Rose Quartz (Silicon Dioxide with traces of Titanium, Iron, or Manganese (SiO2)) — mineral

Rose Quartz

Silicon Dioxide with traces of Titanium, Iron, or Manganese (SiO2)

Travertine (Calcareous Tufa) (Calcium Carbonate (CaCO3)) — sedimentary

Travertine (Calcareous Tufa)

Calcium Carbonate (CaCO3)

Dark rounded pebble, likely basalt (Basalt — fine-grained mafic volcanic rock, mainly plagioclase and pyroxene with possible olivine) — igneous

Dark rounded pebble, likely basalt

Basalt — fine-grained mafic volcanic rock, mainly plagioclase and pyroxene with possible olivine

Larimar (Pectolite (NaCa2Si3O8(OH))) — Mineral variant / Gemstone

Larimar

Pectolite (NaCa2Si3O8(OH))

Mineral variant / Gemstone

Obsidian (Obsidian (volcanic glass), amorphous SiO2 + impurities) — igneous

Obsidian

Obsidian (volcanic glass), amorphous SiO2 + impurities

Howlite (Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)) — Mineral

Howlite

Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)

Obsidian (Volcanic Glass (SiO2, usually 70% or more)) — igneous

Obsidian

Volcanic Glass (SiO2, usually 70% or more)

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

Black Obsidian

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

Chalcedony (Pink/Gray variety) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Pink/Gray variety)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal) (Silicon Dioxide (SiO2)) — mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Obsidian (Obsidian (Volcanic glass, primarily SiO2)) — igneous

Obsidian

Obsidian (Volcanic glass, primarily SiO2)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Obsidian (Volcanic Glass (70% or more SiO2)) — igneous

Obsidian

Volcanic Glass (70% or more SiO2)

Amethyst (Amethyst (Silicon Dioxide, SiO2)) — mineral

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Obsidian (Volcanic Glass (SiO2 with impurities)) — igneous

Obsidian

Volcanic Glass (SiO2 with impurities)