Quartz with Iron Stains
Quartz (SiO2) with iron oxide/hydroxide staining
Mineral
Category
Mixed (Predominantly Sedimentary And Igneous)
Browse mixed (predominantly sedimentary and igneous) specimens identified by the Rock Identifier community.
Aventurine (likely Green Aventurine)
Silicon Dioxide (SiO2) with mineral inclusions
Mineral/Mineraloid within a rock matrix
Schist
Schist (various mineralogical compositions including mica, chlorite, talc, etc.)
Metamorphic
Quartz (Float/Abraded)
Quartz (SiO₂)
Mineral
Pyrite
Iron Pyrite (FeS2)
mineral
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
mineral
Sandstone (Ferruginous)
Arenite (Fe-oxide cemented)
sedimentary
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Iron Oxide cement)
sedimentary
Shale
Fissile Mudstone
sedimentary
Sandstone (Ferruginous)
Clastic Sedimentary Rock (SiO2 with Fe2O3/FeOOH cement)
sedimentary
Felsic Igneous Rock (likely Rhyolite or weathered Granite)
Felsic Volcanic/Plutonic Rock
igneous
Gastropod Steinkern (Internal Mold Fossil)
Gastropoda (Class); Internal mold or 'Steinkern' composed of Calcium Carbonate (CaCO3) or Sedimentary matrix
sedimentary
Yellow Chalcedony
Chalcedony (a cryptocrystalline variety of Quartz, SiO₂)
Mineral
Smoky Quartz
SiO2 (Silicon Dioxide)
Mineral
Calcite
Calcite (CaCO₃, Calcium Carbonate)
Mineral
Amethyst
Quartz (SiO2) variety
Mineral
Marble
Marbles are primarily composed of calcite (calcium carbonate, CaCO3) or dolomite (calcium magnesium carbonate, CaMg(CO3)2).
Metamorphic Rock
Basalt
Basalt (Mafic volcanic rock)
igneous
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Hypersthene (or Enstatite/Ferrosilite)
Orthopyroxene series (Mg,Fe)SiO3 - specifically, historically hypersthene (intermediate member) now referred to as Enstatite (Mg-rich) or Ferrosilite (Fe-rich)
Mineral
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
mineral
Porphyry (likely Porphyritic Andesite or Basalt)
Porphyritic Igneous Rock
igneous
Basalt
Mafic Igneous Rock
igneous
Basalt
Mafic Igneous Rock
igneous
Basalt
Mafic Igneous Basalt
igneous
Basalt
Mafic Igneous Rock
igneous
Basalt
Mafic Igneous Rock
igneous
Basalt River Stone
Basaltic Igneous Rock
igneous
General Rock and Mineral Collection (Center: Angelite / Blue Anhydrite)
Anhydrite (Calcium Sulfate, CaSO4)
Mineral
Natural Gemstone Cabochons (Ruby, Moonstone, Emerald, Citrine)
Ruby (Al2O3:Cr), Moonstone (KAlSi3O8), Emerald (Be3Al2(SiO3)6:Cr), Citrine (SiO2)
mineral
Granite
Phaneritic plutonic rock (SiO2 range 65-75%)
igneous
Milky Quartz with Iron Inclusions
Silicon Dioxide (SiO2)
mineral
Quartz (Iron-Stained)
Silicon Dioxide (SiO2)
mineral
Quartz Geode
Silicon Dioxide (SiO2) in a Geode body
sedimentary or igneous (host environment)
Epidote (or Epidote-rich rock)
Epidote. Mineral formula: Ca2(Al,Fe)3(SiO4)3(OH).
Mineral, often found in metamorphic rocks but also in sedimentary and igneous rocks
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Granite
Granite (Mainly Quartz SiO2 and Feldspar KAlSi3O8)
igneous
Mahogany Obsidian
Volcanic Glass with Hematite or Magnetite inclusions (SiO2 + Fe2O3)
igneous
Granite
Phaneritic Felsic Intrusive Rock
igneous
Banded Sandstone (Zebra Stone)
Arenite with Iron Oxide Banding (Liesegang rings)
sedimentary
Sandstone with Ironstone Concretion
Arenite with Hematite/Goethite nodules (Fe2O3 / FeO(OH))
sedimentary
Granite
Granite (a plutonic rock)
Igneous