Serpentine
Serpentinite (rock) containing serpentine minerals (e.g., Antigorite, Lizardite, Chrysotile)
Metamorphic rock
Category
Metamorphic Or Sedimentary Depending On Local Grade
Browse metamorphic or sedimentary depending on local grade specimens identified by the Rock Identifier community.
Garnet (likely Pyrope or Almandine)
Garnet Group (complex nesosilicate minerals, e.g., Pyrope Mg3Al2(SiO4)3, Almandine Fe3Al2(SiO4)3, Spessartine Mn3Al2(SiO4)3, Grossular Ca3Al2(SiO4)3, Andradite Ca3Fe2(SiO4)3, Uvarovite Ca3Cr2(SiO4)3). The vivid red color in the image strongly suggests Pyrope or Almandine.
Mineral
Rose Quartz
Rose Quartz (SiO₂)
mineral
Green Aventurine
Aventurine (a variety of Quartz, SiO2)
Mineral
Aquamarine
Beryl (Be3Al2Si6O18), specifically the blue-green variety
Mineral
Blue Tiger's Eye
Crocidolite in Quartz (altered)
Mineral
Aragonite Star Cluster
Aragonite (Calcium Carbonate, CaCO3)
mineral
Chert (Yellow Jasper variant)
Silicon Dioxide (SiO2)
sedimentary
Chert (Pink Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
sedimentary
Jet
Lignite (Anthracite-grade compact coal)
sedimentary
Chert (Jasper/Agate variety)
Cryptocrystalline Quartz (SiO2)
sedimentary
Jasper
Jasper (Silica/Silicon Dioxide, SiO2)
sedimentary
Sandstone (specifically Red Sandstone)
Arenite (SiO2 with Iron Oxide)
sedimentary
Jasper-Agate Breccia
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Chert (Jasper/Flint variant)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Sandstone (Ferruginous)
Arenite with Iron Oxide cement
sedimentary
Magnetite
Magnetite (Iron(II,III) oxide, Fe3O4)
mineral
Almandine Garnet in Matrix
Almandine Garnet (Fe3Al2(SiO4)3) in Schist/Quartz Matrix
metamorphic
Specular Hematite (Specularite)
Iron(III) oxide (Fe2O3)
mineral
Rhodonite
Manganese Inosilicate (Mn,Fe,Mg,Ca)SiO3
mineral
Agate
Banded Chalcedony (SiO2)
mineral
Almandine Garnet in Matrix
Almandine, Fe3Al2(SiO4)3
metamorphic
Banded Iron Formation (BIF) / Iron Ore
Banded Iron Formation (composed primarily of Hematite (Fe2O3) and Magnetite (Fe3O4) with Quartz/Chert)
sedimentary
Chert (Yellow Jasper/Agatized Chert)
Microcrystalline Quartz (SiO2)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Jasper with Manganese Dendrites
Silicon Dioxide (SiO2) with Oxide Mineral Inclusions
sedimentary
Puddingstone (Gowganda Tillite/Lorrain Quartzite)
Jasper Conglomerate
sedimentary
Petrified Wood
Silicified wood (Quartz, Chalcedony, or Opal)
sedimentary
Optical Calcite
Calcium Carbonate (CaCO3)
mineral
Chert (often called Jasper or Flint in this color variety)
Silicon Dioxide (SiO2)
sedimentary
Staurolite (Fairy Stone)
Staurolite (formula: Fe2+2Al9Si4O23(OH))
metamorphic
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
metamorphic
Precious Opal
Hydrated Silica (SiO2·nH2O)
mineral
Chert (Jasper-bearing)
Microcrystalline silica (SiO2) with iron oxide inclusions
sedimentary
White Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Mineraloid
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
mineral
Red Jasper (Heliotrope family variant)
Silicon Dioxide with Hematite inclusions (SiO2 + Fe2O3)
sedimentary
Chrysocolla
Hydrated copper phyllosilicate, Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O)
mineral
Conglomerate
Conglomerate
Sedimentary Rock
Caliche (with Lichen Cover)
Calcium carbonate-cemented soil layer (CaCO3)
sedimentary
Sandstone (specifically Arkose or Ferruginous Sandstone)
Sandstone (SiO2 with iron oxide inclusions)
sedimentary
Ironstone Concretion / Goethite Nodules
Ironstone (composed primarily of Goethite FeO(OH) and Limonite)
sedimentary