Rock Identifier

Category

Organic (Often Found By Beachcombers)

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

Scoria (Lava Rock) (Scoria (vesicular basaltic rock)) — igneous

Scoria (Lava Rock)

Scoria (vesicular basaltic rock)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Milky Quartz (or Bull Quartz)

Silicon Dioxide (SiO2)

Milky Quartz (Silicon dioxide (SiO2)) — mineral

Milky Quartz

Silicon dioxide (SiO2)

Porfido (Porphyritic Rock) (Porphyry (often Rhyolitic or Andesitic)) — igneous

Porfido (Porphyritic Rock)

Porphyry (often Rhyolitic or Andesitic)

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

Amethyst

Silicon Dioxide (SiO2) with iron impurities

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

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartzite with Iron Staining (Quartzite (primarily SiO2 with Fe2O3 staining)) — metamorphic

Quartzite with Iron Staining

Quartzite (primarily SiO2 with Fe2O3 staining)

Quartz with Iron Oxide Inclusions (SiO2 with Fe2O3 impurities) — Mineral

Quartz with Iron Oxide Inclusions

SiO2 with Fe2O3 impurities

Greywacke (River/Beach Pebble) (Greywacke (Impure Sandstone)) — sedimentary

Greywacke (River/Beach Pebble)

Greywacke (Impure Sandstone)

Chert (Flint) (Silicon Dioxide (SiO2)) — Sedimentary

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (variations include Flint/Jasper) (Chert (SiO2)) — sedimentary

Chert (variations include Flint/Jasper)

Chert (SiO2)

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

Chert (Flint variety)

Silicon Dioxide (SiO2)

Ironstone Concretion / Limonite-stained Siltstone (Ironstone (primarily Limonite FeO(OH)·nH2O and Siltstone)) — sedimentary

Ironstone Concretion / Limonite-stained Siltstone

Ironstone (primarily Limonite FeO(OH)·nH2O and Siltstone)

Quartz Vein in Host Rock (Gneiss/Schist) (Silicon Dioxide (SiO2) within a metamorphic matrix) — metamorphic

Quartz Vein in Host Rock (Gneiss/Schist)

Silicon Dioxide (SiO2) within a metamorphic matrix

Chert (or possibly Flint) (Chert (variant: Flint)) — Sedimentary

Chert (or possibly Flint)

Chert (variant: Flint)

Banded Rhyolite (likely Green Jasper/Agate variety) (Silicon Dioxide (SiO2) with mineral inclusions) — igneous

Banded Rhyolite (likely Green Jasper/Agate variety)

Silicon Dioxide (SiO2) with mineral inclusions

Quartz (Quartz (SiO₂)) — mineral

Quartz

Quartz (SiO₂)

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

Prehnite

Prehnite, Ca2Al(AlSi3O10)(OH)2

Orange Quartzite (or Iron-Stained Quartz) (Silicon Dioxide (SiO2) with Iron Oxide impurities (Fe2O3)) — metamorphic

Orange Quartzite (or Iron-Stained Quartz)

Silicon Dioxide (SiO2) with Iron Oxide impurities (Fe2O3)

Bornite (Peacock Ore) (Bornite (Copper iron sulfide - Cu5FeS4)) — mineral

Bornite (Peacock Ore)

Bornite (Copper iron sulfide - Cu5FeS4)

Quartzite River Rock (with Limonite staining) (Quartzite (SiO2)) — metamorphic

Quartzite River Rock (with Limonite staining)

Quartzite (SiO2)

Quartzite Pebble (Quartzite (SiO2)) — metamorphic

Quartzite Pebble

Quartzite (SiO2)

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Quartzite (Quartzite (composed primarily of Quartz, SiO2)) — metamorphic

Quartzite

Quartzite (composed primarily of Quartz, SiO2)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Jasper with Quartz Vein (Silicon Dioxide (SiO2) with impurities) — sedimentary

Jasper with Quartz Vein

Silicon Dioxide (SiO2) with impurities

Smoky Quartz (with complementary stones in jewelry setting) (Smoky Quartz (Silicon Dioxide - SiO2)) — mineral

Smoky Quartz (with complementary stones in jewelry setting)

Smoky Quartz (Silicon Dioxide - SiO2)

Red Jasper with Quartz Veining (Jasper (Silicon Dioxide, SiO2) with Quartz (SiO2) inclusions) — sedimentary

Red Jasper with Quartz Veining

Jasper (Silicon Dioxide, SiO2) with Quartz (SiO2) inclusions

Quartzite (Quartzite (Primary mineral: SiO2)) — metamorphic

Quartzite

Quartzite (Primary mineral: SiO2)

Peridotite (with Olivine and Pyroxene) (Ultramafic Magmatic Rock (Primary minerals: (Mg, Fe)2SiO4 and (Ca, Mg, Fe)2Si2O6)) — igneous

Peridotite (with Olivine and Pyroxene)

Ultramafic Magmatic Rock (Primary minerals: (Mg, Fe)2SiO4 and (Ca, Mg, Fe)2Si2O6)

Chert Pebble (Jasperoid/Flint) (Silicon Dioxide (SiO2) - cryptocrystalline quartz) — Sedimentary

Chert Pebble (Jasperoid/Flint)

Silicon Dioxide (SiO2) - cryptocrystalline quartz

Dolomite (Dolomite (CaMg(CO3)2)) — Mineral

Dolomite

Dolomite (CaMg(CO3)2)

Goethite (Goethite (α-FeO(OH))) — Mineral

Goethite

Goethite (α-FeO(OH))

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Quartzite Pebble (Metamorphosed Sandstone (SiO2)) — metamorphic

Quartzite Pebble

Metamorphosed Sandstone (SiO2)

Chlorite (Small Flakes/Sand) (Chlorite Group (Magnesium Iron Aluminum Silicate Hydroxide - (Mg,Fe)3(Si,Al)4O10(OH)2·(Mg,Fe)3(OH)6)) — mineral

Chlorite (Small Flakes/Sand)

Chlorite Group (Magnesium Iron Aluminum Silicate Hydroxide - (Mg,Fe)3(Si,Al)4O10(OH)2·(Mg,Fe)3(OH)6)

Peridotite (Peridotite (Ultramafic Rock)) — igneous

Peridotite

Peridotite (Ultramafic Rock)

Malachite (Copper carbonate hydroxide, Cu2CO3(OH)2) — mineral

Malachite

Copper carbonate hydroxide, Cu2CO3(OH)2

Ferrous Slag (Fused calcium-iron silicates (Industrial Slag)) — Anthropogenic/Industrial byproduct

Ferrous Slag

Fused calcium-iron silicates (Industrial Slag)

Anthropogenic/Industrial byproduct

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

Howlite

Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)