Rock Identifier

Category

Organic (Often Found By Beachcombers)

Browse organic (often found by beachcombers) specimens identified by the Rock Identifier community.

Fossilized Coral (Petoskey-like or Favosites) (Anthozoa (Fossilized Coral)) — sedimentary

Fossilized Coral (Petoskey-like or Favosites)

Anthozoa (Fossilized Coral)

Ironstone Concretion (Moqui Marble type) (Iron oxide concretion (Goethite/Hematite and Sandstone)) — sedimentary

Ironstone Concretion (Moqui Marble type)

Iron oxide concretion (Goethite/Hematite and Sandstone)

Rhodonite (Manganese Silicate (Mn,Fe,Mg,Ca)SiO3) — mineral

Rhodonite

Manganese Silicate (Mn,Fe,Mg,Ca)SiO3

Citrine Quartz (Silicon Dioxide (SiO2)) — mineral

Citrine Quartz

Silicon Dioxide (SiO2)

Red Swirl Beads (Likely Resin or Glass, simulating Red Jasper or Agate) (N/A (for the beads as pictured); Red Jasper: SiO2 (Chert variety); Red Agate: SiO2 (Chalcedony variety)) — Organic (if resin) or Synthetic (if glass); simulating Sedimentary or Metamorphic (for natural stones)

Red Swirl Beads (Likely Resin or Glass, simulating Red Jasper or Agate)

N/A (for the beads as pictured); Red Jasper: SiO2 (Chert variety); Red Agate: SiO2 (Chalcedony variety)

Organic (if resin) or Synthetic (if glass); simulating Sedimentary or Metamorphic (for natural stones)

Quartzite Pebble (Meta-quartzite) — metamorphic

Quartzite Pebble

Meta-quartzite

Chalcopyrite (Chalcopyrite (CuFeS2)) — Mineral

Chalcopyrite

Chalcopyrite (CuFeS2)

Chalcedony (Chalcedony (a microcrystalline variety of Quartz, SiO2)) — Mineral

Chalcedony

Chalcedony (a microcrystalline variety of Quartz, SiO2)

Pyrite (Pyrite (FeS2)) — Mineral

Pyrite

Pyrite (FeS2)

Aquamarine (Beryl (Be3Al2Si6O18)) — mineral

Aquamarine

Beryl (Be3Al2Si6O18)

Rhodonite ((Mn,Fe,Mg,Ca)SiO3) — mineral

Rhodonite

(Mn,Fe,Mg,Ca)SiO3

Chrysocolla (Chrysocolla, (Cu, Al)2H2Si2O5(OH)4·nH2O) — mineral

Chrysocolla

Chrysocolla, (Cu, Al)2H2Si2O5(OH)4·nH2O

Lazulite (Magnesium Aluminum Phosphate Hydroxide (MgAl2(PO4)2(OH)2)) — mineral

Lazulite

Magnesium Aluminum Phosphate Hydroxide (MgAl2(PO4)2(OH)2)

Quartzite Pebbles (Quartzite (primarily SiO2)) — metamorphic

Quartzite Pebbles

Quartzite (primarily SiO2)

Amber (Amber (Fossilized Tree Resin)) — Mineral

Amber

Amber (Fossilized Tree Resin)

Jasper (likely Brecciated or Multi-colored) (Jasper (SiO2)) — sedimentary

Jasper (likely Brecciated or Multi-colored)

Jasper (SiO2)

Magnetite (Magnetite (Fe3O4)) — mineral

Magnetite

Magnetite (Fe3O4)

Chrysocolla (Chrysocolla (Cu,Al)2H2Si2O5(OH)4·nH2O) — Mineral

Chrysocolla

Chrysocolla (Cu,Al)2H2Si2O5(OH)4·nH2O

Chert Nodule (Microcrystalline Quartz (SiO2)) — sedimentary

Chert Nodule

Microcrystalline Quartz (SiO2)

Fluorite (Calcium Fluoride (CaF2)) — mineral

Fluorite

Calcium Fluoride (CaF2)

Iron-stained Quartzite (Quartzite with Limonite/Hematite staining (SiO2 with FeO(OH)·nH2O)) — metamorphic

Iron-stained Quartzite

Quartzite with Limonite/Hematite staining (SiO2 with FeO(OH)·nH2O)

Goethite (likely as part of Limonite/Ironstone) (Goethite (α-FeOOH)) — Mineral

Goethite (likely as part of Limonite/Ironstone)

Goethite (α-FeOOH)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Quartzite Pebble (Metamorphosed Quartz Sandstone (SiO2)) — metamorphic

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Terrazzo (Man-made Composite) (Cementitious or Resin-bound Lithic Composite) — sedimentary (artificial)

Terrazzo (Man-made Composite)

Cementitious or Resin-bound Lithic Composite

sedimentary (artificial)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Ruby (Corundum (Al2O3 with Chromium impurities)) — mineral

Ruby

Corundum (Al2O3 with Chromium impurities)

Coprolite (Fossilized feces (various taxa)) — sedimentary

Coprolite

Fossilized feces (various taxa)

Magnetite (Magnetite (Fe3O4)) — Mineral

Magnetite

Magnetite (Fe3O4)

Quartzite (River Pebble) (Metamorphic Quartzite (primarily SiO2)) — metamorphic

Quartzite (River Pebble)

Metamorphic Quartzite (primarily SiO2)

Lepidolite Polished Point (Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)) — mineral

Lepidolite Polished Point

Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)

Glauconitic Sandstone (Glauconitic Sandstone (Greensand)) — sedimentary

Glauconitic Sandstone

Glauconitic Sandstone (Greensand)

Rhodonite (Rhodonite (MnSiO3)) — Mineral

Rhodonite

Rhodonite (MnSiO3)

Banded Calcite (Mexican Onyx) (Calcium Carbonate (CaCO3)) — mineral

Banded Calcite (Mexican Onyx)

Calcium Carbonate (CaCO3)

Quartz Pebble (Sea Glass-like texture) (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble (Sea Glass-like texture)

Silicon Dioxide (SiO2)

Jasper in Basalt Matrix (Silicon Dioxide (SiO2) with impurities; Chalcedony) — sedimentary (secondary mineral) within igneous

Jasper in Basalt Matrix

Silicon Dioxide (SiO2) with impurities; Chalcedony

sedimentary (secondary mineral) within igneous

Manganese Oxide Crust on Limestone (Manganese Oxides (e.g., Pyrolusite MnO2 or Romanechite) on CaCO3) — sedimentary

Manganese Oxide Crust on Limestone

Manganese Oxides (e.g., Pyrolusite MnO2 or Romanechite) on CaCO3

Banded Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Banded Chert

Microcrystalline Quartz (SiO2)

Jasper (likely a variety of Brecciated Jasper or a patterned variety) (Silicon dioxide (SiO2)) — Mineral

Jasper (likely a variety of Brecciated Jasper or a patterned variety)

Silicon dioxide (SiO2)

Blue Quartz (Quartz (SiO2) with inclusions) — Mineral

Blue Quartz

Quartz (SiO2) with inclusions

Banded Quartzite (Quartzite (SiO2 with impurities)) — metamorphic

Banded Quartzite

Quartzite (SiO2 with impurities)