Sedimentary Or Igneous (Host Environment)

Browse sedimentary or igneous (host environment) specimens identified by the Rock Identifier community.

Petrified Wood

Silicified Wood (SiO2)

metamorphic

Chalcedony on Matrix (Botryoidal Agate)

Silicon Dioxide (SiO2)

mineral

Emerald in Matrix

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

mineral

Banded Quartz

Silicon Dioxide (SiO2)

mineral

Vanadinite

Lead Chlorovanadate - Pb5(VO4)3Cl

mineral

Placer Gold Nugget

Native Gold (Au)

mineral

Dendritic Opal

Dendritic Common Opal (SiO2·nH2O with Manganese oxide inclusions)

mineral

Ruby in Fuchsite (often confused with Ruby in Zoisite)

Corundum (Al2O3) in Chromium-rich Muscovite (KAl2(AlSi3O10)(OH)2)

metamorphic

Carnelian Agate

Silicon Dioxide (SiO2)

mineral

Mixed Gemstone Bracelet

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

Mineral/Rock assemblage

Chalcedony (Agate)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

mineral

Arkosic Sandstone (or Conglomeritic Sandstone fragment)

Arkose (rich in feldspar)

sedimentary

Chert (Iron-stained River Cobble)

Microcrystalline Quartz (SiO2)

sedimentary

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)

Banded River Rock / Gneiss (highly weathered)

Gneiss

Metamorphic rock

Red Sandstone

Arenite (ferruginous sandstone)

sedimentary

Diorite (Dalmatian Stone)

Phaneritic Plutonic Diorite

igneous

Shale (possibly)

Shale (fine-grained clastic sedimentary rock)

sedimentary

Sandstone (Micaceous Sandstone)

Arenite (SiO2 with KAl2(AlSi3O10)(OH)2 inclusions)

sedimentary

Sandstone with Trace Fossils

Arenite with Ichnofossils

sedimentary

Orange Calcite

Calcite (CaCO3)

Mineral

Quartz Vein in Host Rock (likely Sandstone or Mudstone)

Silicon Dioxide (SiO2) within Sedimentary Matrix

sedimentary

Quartz Vein in Host Rock (clastic sediment)

Silicon Dioxide (SiO2) in matrix

sedimentary

Jasper-Agate

Silicon Dioxide (SiO2) - Microcrystalline Quartz

sedimentary

Milky Quartz

Silicon Dioxide (SiO2)

mineral

Pyrite

Iron Disulfide (FeS2)

mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

mineral

Pyrite

Iron Sulfide (FeS2)

mineral

White Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

mineral

Biotite (Black Mica)

Biotite (K(Mg,Fe)3AlSi3O10(OH)2)

mineral

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

mineral

Quartz (Milky/Common variant)

Silicon Dioxide (SiO2)

mineral

Magnetite (Lodestone variety)

Magnetite (Iron(II,III) oxide, Fe3O4)

mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

mineral

Clear Quartz

Silicon Dioxide (SiO2)

mineral

Clear Quartz

Silicon Dioxide (SiO2)

mineral

Carnelian Agate

Chalcedony (SiO2) with iron oxide inclusions

mineral

Black Onyx

Cryptocrystalline Quartz (SiO2 with organic/iron impurities)

mineral

Quartz with Limonite Staining

Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)

Mineral

Garnet in Matrix (Eclogite)

Eclogite, featuring Almandine or Pyrope Garnet [X3Y2(SiO4)3]

metamorphic

Amethyst (Agate/Chalcedony variety)

Silicon Dioxide (SiO2) with iron impurities

mineral

Rutilated Prehnite

Prehnite - Ca2Al(AlSi3O10)(OH)2 with Epidote/Tourmaline inclusions

mineral