Rock Identifier

Category

Organic (Often Found By Beachcombers)

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

Sandstone (Arenite (composed primarily of SiO2)) — sedimentary

Sandstone

Arenite (composed primarily of SiO2)

Quartz on Basalt (Silicon Dioxide (SiO2) on Mafic Igneous Rock) — Mineral on Igneous Rock

Quartz on Basalt

Silicon Dioxide (SiO2) on Mafic Igneous Rock

Mineral on Igneous Rock

Sandstone (Ferruginous) (Arenite (primarily SiO2 with iron oxide cement)) — sedimentary

Sandstone (Ferruginous)

Arenite (primarily SiO2 with iron oxide cement)

Sandstone (Ferruginous) (Arenite (composed primarily of SiO2 with Fe2O3 staining)) — sedimentary

Sandstone (Ferruginous)

Arenite (composed primarily of SiO2 with Fe2O3 staining)

Vesicular Basalt (Vesicular Basalt (Aphanitic Mafic Igneous Rock)) — igneous

Vesicular Basalt

Vesicular Basalt (Aphanitic Mafic Igneous Rock)

Serpentine (Serpentine-group (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4) — metamorphic

Serpentine

Serpentine-group (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4

Basalt (Basalt (Mafic Extrusive)) — igneous

Basalt

Basalt (Mafic Extrusive)

Rose Quartz (Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese) — mineral

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Basalt (Basalt) — igneous

Basalt

Basalt

Smoky Quartz (Quartz (Silicon Dioxide, SiO2)) — mineral

Smoky Quartz

Quartz (Silicon Dioxide, SiO2)

Tiger's Eye (Pseudomorph of quartz after crocidolite (SiO2)) — metamorphic

Tiger's Eye

Pseudomorph of quartz after crocidolite (SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz (Quartz (Silicon Dioxide - SiO2)) — mineral

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

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

Mahogany Obsidian

Volcanic Glass with Hematite inclusions (SiO2 + Fe2O3)

Amazonite (Microcline (variety Amazonite) - K(AlSi3O8)) — mineral

Amazonite

Microcline (variety Amazonite) - K(AlSi3O8)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Quartzite with Iron Inclusions (Metamorphic Quartzite (SiO2 with Fe2O3 trace impurities)) — metamorphic

Quartzite with Iron Inclusions

Metamorphic Quartzite (SiO2 with Fe2O3 trace impurities)

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

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Ironstone Nodule (Ironstone Concretion) (Siderite-rich Mudstone (FeCO3) or Limonite (FeO(OH)·nH2O)) — sedimentary

Ironstone Nodule (Ironstone Concretion)

Siderite-rich Mudstone (FeCO3) or Limonite (FeO(OH)·nH2O)

Carnelian Agate (Carnelian (Silicon Dioxide: SiO2) with iron oxide impurities) — mineral

Carnelian Agate

Carnelian (Silicon Dioxide: SiO2) with iron oxide impurities

Quartzite (Metamorphosed Quartz Sandstone (SiO2)) — metamorphic

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

Red Quartzite (Quartzite (SiO2)) — metamorphic

Red Quartzite

Quartzite (SiO2)

Smoky Quartz (Smoky Quartz (Silicon Dioxide, SiO2)) — mineral

Smoky Quartz

Smoky Quartz (Silicon Dioxide, SiO2)

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

Gold (Native Gold (Au)) — mineral

Gold

Native Gold (Au)

Geode with Quartz/Chalcedony (Silicon Dioxide (SiO2)) — sedimentary

Geode with Quartz/Chalcedony

Silicon Dioxide (SiO2)

Fossiliferous Limestone (with Coralline Inclusions) (Calcium Carbonate (CaCO3)) — sedimentary

Fossiliferous Limestone (with Coralline Inclusions)

Calcium Carbonate (CaCO3)

Quartzite (River Pebble) (Metamorphic rock consisting primarily of Quartz (SiO2)) — metamorphic

Quartzite (River Pebble)

Metamorphic rock consisting primarily of Quartz (SiO2)

Banded Calcite (often marketed as Caribbean Calcite) (Calcium Carbonate (CaCO3) + Aragonite) — sedimentary

Banded Calcite (often marketed as Caribbean Calcite)

Calcium Carbonate (CaCO3) + Aragonite

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Copper Ore with Malachite and Chrysocolla (Cu2CO3(OH)2 (Malachite) with Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Chrysocolla)) — mineral

Copper Ore with Malachite and Chrysocolla

Cu2CO3(OH)2 (Malachite) with Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Chrysocolla)

Fuchsite (Green Muscovite) (K(Al,Cr)2(AlSi3O10)(OH)2) — mineral

Fuchsite (Green Muscovite)

K(Al,Cr)2(AlSi3O10)(OH)2

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

Diorite

Diorite (Intermediate intrusive igneous rock)

Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Granite (Phaneritic Felsic Igneous Rock) — igneous

Granite

Phaneritic Felsic Igneous Rock

Basalt with Scoria (Mafic Volcanic Rock (Basalt/Scoria)) — igneous

Basalt with Scoria

Mafic Volcanic Rock (Basalt/Scoria)

Basalt (Basalt (Mafic Extrusive)) — igneous

Basalt

Basalt (Mafic Extrusive)

Banded Jasper with Hematite or Quartz (Silicon Dioxide (SiO2) with impurities) — sedimentary

Banded Jasper with Hematite or Quartz

Silicon Dioxide (SiO2) with impurities

Yellow Chalcedony (common opal or chert variant) (Silicon Dioxide (SiO2)) — sedimentary (mineraloid/microcrystalline quartz)

Yellow Chalcedony (common opal or chert variant)

Silicon Dioxide (SiO2)

sedimentary (mineraloid/microcrystalline quartz)

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

Quartzite (Quartzite (SiO2-dominant rock)) — metamorphic

Quartzite

Quartzite (SiO2-dominant rock)

Unakite (Unakite (Epidotized Granite)) — metamorphic

Unakite

Unakite (Epidotized Granite)