Sedimentary (Chemically Precipitated) Or Metamorphic

Browse sedimentary (chemically precipitated) or metamorphic specimens identified by the Rock Identifier community.

Magnetite / Iron-Rich Concretion

Magnetite (Fe3O4) or Bog Iron Limonite

mineral

Chrysocolla and Azurite on Matrix

Hydrated copper silicate (Cu,Al)2H2Si2O5(OH)4 (Chrysocolla) and Copper carbonate hydroxide Cu3(CO3)2(OH)2 (Azurite)

mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

mineral

Botryoidal Malachite

Malachite - Cu2CO3(OH)2

mineral

Quartzite

Quartzite (primarily SiO2)

Metamorphic

Red Jasper (Opaque Chalcedony)

Silicon Dioxide (SiO2) with Hematite inclusions

sedimentary

Yellow Jasper

Silicon Dioxide (SiO2) with Goethite/Iron oxide impurities

sedimentary (chemical)

Ferruginous Quartz

Silicon Dioxide (SiO2) with Hematite/Limonite impurities

mineral

Mahogany Obsidian

Obsidian (volcanic glass with Hematite/Magnetite inclusions)

igneous

Mahogany Obsidian

Obsidian (Volcanic Glass) with Hematite or Magnetite inclusions, SiO2 (Silicon Dioxide)

igneous

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

mineral

Quartz Pebble

Silicon Dioxide (SiO2)

mineral

Gneiss

Gneiss (High-grade metamorphic rock typically composed of Quartz, Feldspar, and Mica/Amphibole)

metamorphic

Quartz (Milky/Cloudy Variety)

Silicon Dioxide (SiO2)

mineral

Pyrite

Iron Disulfide (FeS2)

mineral

Schorl (Black Tourmaline)

Sodium Iron Aluminum Borosilicate (NaFe3Al6(BO3)3Si6O18(OH)4)

mineral

Quartz Druze

Silicon Dioxide (SiO2)

mineral

Rhodochrosite with Pyrite and Quartz

Manganese Carbonate (MnCO3)

mineral

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide inclusions

mineral

Amethyst

Silicon Dioxide (SiO2) with Iron impurities

mineral

Dendritic Agate (Tumbled)

Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions

mineral

Moss Agate

Silicon Dioxide (SiO2) with Chlorite/Oxide inclusions

mineral

Green Fluorite

Fluorite (Calcium Fluoride, CaF2)

mineral

Ocean Jasper

Spherulitic Chalcedony (SiO2)

mineral

Quartz Veined Basalt

Mafic Volcanic Rock with Microcrystalline Quartz (SiO2)

igneous

Gneiss

Gneiss (High-grade regional metamorphic rock)

metamorphic

Dragon Blood Jasper

Epidote with Red Jasper inclusions (SiO2 and Ca2(Al,Fe)3(SiO4)3(OH))

metamorphic

Green Aventurine

Silicon Dioxide (Quartz) with inclusions of Fuchsite mica; Chemical formula: SiO2 + K(Al,Cr)2AlSi3O10(OH)2

metamorphic

Jasper and Basalt Mix (Dark Chert/Basalt River Pebble)

Silicon Dioxide (SiO2) or Mafic extrusive igneous rock

sedimentary or igneous

Rough Garnet (Almandine)

Almandine Garnet (Fe3Al2(SiO4)3)

mineral

Mixed Gemstone Bracelet

Mixed natural minerals and rocks (e.g., Rhodonite, Malachite, Sodalite, Rose Quartz, Black Tourmaline, Quartz/Chalcedony variants)

Mineral/Rock assemblage

Gneiss

Gneiss (High-grade metamorphic rock composed primarily of Quartz, Feldspar, and various Micas)

metamorphic

Blue Goldstone

Aventurine Glass (Silicon Dioxide infused with Cobalt/Copper)

Synthetic (Man-made Glass)

Marble

Marbles are primarily composed of calcite (calcium carbonate, CaCO3) or dolomite (calcium magnesium carbonate, CaMg(CO3)2).

Metamorphic Rock

Concretion or Geode (unbroken)

Varied (depending on mineral composition and cementing agent). For quartz-lined geodes, the scientific name of the dominant mineral would be Quartz (SiO2). For calcite-lined geodes, Calcite (CaCO3). Concretions are often composed of cryptocrystalline quartz (chert), calcite, or iron oxides.

Sedimentary rock (specifically a concretion or possibly a geode)