Magnetite with Quartz
Magnetite (Fe3O4)
mineral
Category
Metamorphic Rock
Browse metamorphic rock specimens identified by the Rock Identifier community.
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Sandstone (with secondary weathering/concretion)
Arenite (composed primarily of Quartz, SiO2)
sedimentary
Granite Pebble
Felsic Igneous Rock (Granitic composition)
igneous
Epidote in Quartz (Unakite-like specimen)
Epidote (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH)) in Quartz (SiO2)
metamorphic
Prasiolite and Quartz Crystal Cluster
Quartz (SiO2); Prasiolite is a variety of Quartz
mineral
Agate (specifically, multi-colored or pastel-dyed agate)
Silicon dioxide (SiO2) - specifically, a cryptocrystalline variety of quartz known as Chalcedony, with banding classified as Agate. (If it were Fluorite, the chemical formula would be Calcium Fluoride - CaF2).
Mineral
Biotite on Matrix
Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)
mineral
Ruby in Kyanite
Corundum in Disthene (Al2SiO5 + Al2O3)
metamorphic
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Yellow Jade (Nephrite)
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
metamorphic
Rhodonite
Rhodonite (Manganese Iron Magnesium Calcium Silicate) - (Mn+2,Fe+2,Mg,Ca)SiO3
mineral
Blue Sapphire (in a faceted jewelry setting)
Corundum (Al2O3) with trace Iron and Titanium
mineral
Actinolite
Ca2(Mg,Fe)5Si8O22(OH)2
mineral
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Limonite (after Pyrite Pseudomorph)
Limonite (Hydrated Iron Oxide Mixture, FeO(OH)·nH2O)
mineral
Quartz Geode
Quartz (Silicon Dioxide - SiO2) within a Chalcedony and Limonite shell
sedimentary
Gneiss
Metamorphic Gneiss (High-grade regional metamorphism)
metamorphic
Gneiss
Metamorphic Gneiss (High-grade regional metamorphism)
metamorphic
Agate Geode with Quartz Druzy
Chalcedony (SiO2) and Quartz (SiO2)
mineral
Quartz (likely milky quartz or a stained variety)
Silicon Dioxide (SiO₂)
Mineral
Note: Item is not a geological specimen
n/a
none
Pink Feldspar
Potassium Feldspar (KAlSi3O8)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Smoky Quartz (with inclusions)
Silicon Dioxide (SiO2)
mineral
Amethyst
Silicon Dioxide (SiO2) with Iron impurities
mineral
Chert (Arrowhead)
Chert (primarily Microcrystalline Silica, SiO2)
sedimentary
Banded Sandstone
Arenite with Liesegang banding (primarily SiO2 with FeO(OH) impurities)
sedimentary
Rhodonite
Manganese Inosilicate (Mn,Fe,Mg,Ca)SiO3
mineral
Prehnite
Prehnite (Ca2Al2Si3O10(OH)2)
mineral
Quartz Vein in Siltstone
Siltstone with Quartz (SiO2) inclusion
sedimentary
Quartz Geode with Chalcedony
Silicon Dioxide (SiO2) in Geode Form
sedimentary
Quartz Geode
Silicon Dioxide (SiO2) within a geode
mineral
Basalt with Calcite Veins
Basalt (Mafic Volcanic Rock)
igneous
Basalt
Basalt (Mafic volcanic rock)
igneous
Kyanite
Kyanite (Al2SiO5)
mineral
Garnet in Matrix (Schist or Quartz)
Almandine Garnet, Fe3Al2(SiO4)3
metamorphic
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Nephrite Jade
Ca2(Mg, Fe)5Si8O22(OH)2
metamorphic
Quartz (likely Yellow/Orange variety, possibly Citrine or Chalcedony with iron staining)
Quartz (SiO₂)
Mineral
Gneiss
Gneiss
metamorphic