Rock Identifier

Category

Limestone

Browse limestone specimens identified by the Rock Identifier community.

Marble (Marble (metamorphosed limestone or dolostone), primarily composed of calcite (CaCO3) or dolomite (CaMg(CO3)2)) — metamorphic

Marble

Marble (metamorphosed limestone or dolostone), primarily composed of calcite (CaCO3) or dolomite (CaMg(CO3)2)

Red Jasper or Chert (Jasper (SiO2, a variety of chalcedony with iron oxide impurities), Chert (SiO2)) — sedimentary

Red Jasper or Chert

Jasper (SiO2, a variety of chalcedony with iron oxide impurities), Chert (SiO2)

Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

Fluorite (Calcium Fluoride (CaF2)) — mineral

Fluorite

Calcium Fluoride (CaF2)

Nephrite Jade (Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2)) — Metamorphic

Nephrite Jade

Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2)

Chrome Diopside (Diopside (Magnesium Calcium Silicate) - CaMgSi2O6 + Cr) — mineral

Chrome Diopside

Diopside (Magnesium Calcium Silicate) - CaMgSi2O6 + Cr

Jasper (Jasper (Silicon Dioxide, SiO2)) — sedimentary

Jasper

Jasper (Silicon Dioxide, SiO2)

Agate with Quartz Druzy (Silicon Dioxide (SiO2) - Microcrystalline and Macrocrystalline varieties) — mineral

Agate with Quartz Druzy

Silicon Dioxide (SiO2) - Microcrystalline and Macrocrystalline varieties

Dendrite (Manganese Oxide Dendrites) (Psilomelane or Pyrolusite on Matrix (typically MnO2)) — mineral

Dendrite (Manganese Oxide Dendrites)

Psilomelane or Pyrolusite on Matrix (typically MnO2)

Chert (specifically Jasper or Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Jasper or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Oolitic Limestone (Egg Stone) (Oolite (Chemical sedimentary rock, primarily CaCO3)) — sedimentary

Oolitic Limestone (Egg Stone)

Oolite (Chemical sedimentary rock, primarily CaCO3)

Chert (and Limestone) River Cobble (Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)) — sedimentary

Chert (and Limestone) River Cobble

Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)

Ammonite Fossil in Limestone Matrix (Ammonoidea (subclass) in Calcium Carbonate (CaCO3)) — sedimentary

Ammonite Fossil in Limestone Matrix

Ammonoidea (subclass) in Calcium Carbonate (CaCO3)

Fossilized Favosites (Honeycomb Coral) (Favosites (Genus), Phylum Cnidaria, Class Anthozoa) — sedimentary

Fossilized Favosites (Honeycomb Coral)

Favosites (Genus), Phylum Cnidaria, Class Anthozoa

Quartz Geode (Silicon Dioxide (SiO2) in Geode form) — sedimentary

Quartz Geode

Silicon Dioxide (SiO2) in Geode form

Green Fluorite (Calcium Fluoride (CaF2)) — mineral

Green Fluorite

Calcium Fluoride (CaF2)

Fossilized Coral (Coquina/Limestone) (Cnidaria Anthozoa (Fossilized)) — sedimentary

Fossilized Coral (Coquina/Limestone)

Cnidaria Anthozoa (Fossilized)

Yellow Jade (often Serpentine or Dolomite) (Primarily Serpentine (Mg3Si2O5(OH)4) or Dolomite (CaMg(CO3)2), though the term 'yellow jade' is also sometimes applied to varieties of true nephrite or jadeite.) — Mineral, often a rock given its aggregate nature

Yellow Jade (often Serpentine or Dolomite)

Primarily Serpentine (Mg3Si2O5(OH)4) or Dolomite (CaMg(CO3)2), though the term 'yellow jade' is also sometimes applied to varieties of true nephrite or jadeite.

Mineral, often a rock given its aggregate nature

Calcite (Yellow/Orange variety - sometimes called Honey Calcite) (Calcite) — Mineral

Calcite (Yellow/Orange variety - sometimes called Honey Calcite)

Calcite

Lapis Lazuli (Lapis Lazuli (a rock composed primarily of Lazurite, Sodalite, Calcite, and Pyrite)) — Mineral

Lapis Lazuli

Lapis Lazuli (a rock composed primarily of Lazurite, Sodalite, Calcite, and Pyrite)

Septarian Nodule (Dragon Stone) (Septarian (composed of Calcite CaCO3, Aragonite CaCO3, and Limestone/Clay)) — sedimentary

Septarian Nodule (Dragon Stone)

Septarian (composed of Calcite CaCO3, Aragonite CaCO3, and Limestone/Clay)

Calligraphy Stone (Mariam Jasper (Fossiliferous Limestone composed of Hematite and Shell remains)) — sedimentary

Calligraphy Stone

Mariam Jasper (Fossiliferous Limestone composed of Hematite and Shell remains)

Septarian Nodule (Septarian concretion (Complex mixture of Siderite/Limestone, Calcite, and Aragonite)) — sedimentary

Septarian Nodule

Septarian concretion (Complex mixture of Siderite/Limestone, Calcite, and Aragonite)

Green Fluorite (Calcium Fluoride (CaF2)) — mineral

Green Fluorite

Calcium Fluoride (CaF2)

Fluorite with Rhodochrosite (Fluorite (CaF2) and Rhodochrosite (MnCO3)) — Mineral

Fluorite with Rhodochrosite

Fluorite (CaF2) and Rhodochrosite (MnCO3)

Chert (or Flint) (Chert (a cryptocrystalline variety of quartz, SiO2)) — sedimentary

Chert (or Flint)

Chert (a cryptocrystalline variety of quartz, SiO2)

Quartz Druze on Matrix (Silicon Dioxide (SiO2)) — mineral

Quartz Druze on Matrix

Silicon Dioxide (SiO2)

Lapis Lazuli (Lazurite crystals on Marble) (Lazurite / (Na,Ca)8[(S,Cl,SO4,OH)2|(AlSiO4)6]) — metamorphic

Lapis Lazuli (Lazurite crystals on Marble)

Lazurite / (Na,Ca)8[(S,Cl,SO4,OH)2|(AlSiO4)6]

Green Calcite (Calcite (CaCO3)) — mineral

Green Calcite

Calcite (CaCO3)

Calcite (commonly referred to as Orange Calcite or Honey Calcite given its color) (Calcite) — Mineral

Calcite (commonly referred to as Orange Calcite or Honey Calcite given its color)

Calcite

Chert (Chert (microcrystalline quartz, SiO2)) — Sedimentary

Chert

Chert (microcrystalline quartz, SiO2)

Rough Corundum (likely Sapphire or Common Corundum) (Aluminum oxide (Al2O3)) — mineral

Rough Corundum (likely Sapphire or Common Corundum)

Aluminum oxide (Al2O3)

Orange Calcite (Calcite (CaCO3)) — Mineral

Orange Calcite

Calcite (CaCO3)

Chert or Flint (polished/water-worn) (Chert (a microcrystalline or cryptocrystalline variety of quartz, SiO2). Flint is a specific variety of chert.) — Sedimentary (most likely, as Chert is a sedimentary rock often found as nodules in limestone or as bedded deposits; however, it can also form by metasomatic replacement, which leans towards metamorphic processes under certain conditions)

Chert or Flint (polished/water-worn)

Chert (a microcrystalline or cryptocrystalline variety of quartz, SiO2). Flint is a specific variety of chert.

Sedimentary (most likely, as Chert is a sedimentary rock often found as nodules in limestone or as bedded deposits; however, it can also form by metasomatic replacement, which leans towards metamorphic processes under certain conditions)

Calcite (Calcite (CaCO₃, Calcium Carbonate)) — Mineral

Calcite

Calcite (CaCO₃, Calcium Carbonate)

Calcite (Calcite (Mineral; CaCO₃)) — Mineral

Calcite

Calcite (Mineral; CaCO₃)

Chert (Arrowhead or Projectile Point) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Arrowhead or Projectile Point)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petoskey Stone (Hexagonaria percarinata (Fossilized colonial coral)) — sedimentary

Petoskey Stone

Hexagonaria percarinata (Fossilized colonial coral)

Calcite (likely a tumbled specimen) (Calcite (CaCO
3
)) — Mineral

Calcite (likely a tumbled specimen)

Calcite (CaCO 3 )

Crushed Stone (Gravel/Aggregates) (Crushed rock aggregate (varied composition including Granite, Limestone, and Quartz)) — sedimentary and igneous (mixed)

Crushed Stone (Gravel/Aggregates)

Crushed rock aggregate (varied composition including Granite, Limestone, and Quartz)

sedimentary and igneous (mixed)

Chert (or possibly Flint) (SiO2 (Silicon Dioxide)) — Sedimentary Rock

Chert (or possibly Flint)

SiO2 (Silicon Dioxide)

Sedimentary Rock