Gneiss
Gneiss (High-Grade Metamorphic Rock)
metamorphic
Category
Sedimentary (Secondary Mineral) Within Igneous
Browse sedimentary (secondary mineral) within igneous specimens identified by the Rock Identifier community.
Learn about Sedimentary (Secondary Mineral) Within Igneous in the encyclopedia
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Pyrite
Iron Disulfide (FeS2)
mineral
Blue Chalcedony
Cryptocrystalline Quartz (SiO2)
mineral
Milky Quartz (Vein Quartz)
Silicon Dioxide (SiO2)
mineral
Quartz with Iron Oxide Inclusions
Silicon Dioxide (SiO2) with Hematite/Limonite
mineral
Agate (Plume or Moss Agate variant)
Chalcedony (SiO2) with various inclusions
mineral
Agate
Silicon Dioxide (SiO2) - variety of Chalcedony
mineral
Limestone with Calcite Crust
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Quartz-rich pegmatite (likely feldspar–quartz rock)
Granitic pegmatite; chiefly quartz (SiO₂) and feldspar, with possible mica/iron-oxide staining
igneous
Druzy Quartz
Crystalline Silicon Dioxide (SiO2)
mineral
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrous ferric oxide)
mineral
Limestone with Calcite Crystals
Calcium Carbonate (CaCO3)
sedimentary
Labradorite
Plagioclase Feldspar (Na,Ca)(Al,Si)4O8
mineral
Copper-bearing Quartz (with Malachite and Iron Oxides)
Quartz (SiO2) with Malachite (Cu2CO3(OH)2) and Hematite/Limonite (Fe2O3)
Mineral Specimen
Iron-Stained Quartz (Red/Hematoid Quartz)
Silicon Dioxide (SiO2) with Hematite/Goethite inclusions
mineral
Quartz with Iron Staining
Silicon Dioxide (SiO2) with iron oxide impurities
mineral
Gneiss
Gneiss
metamorphic
Gneiss with Quartz Veining
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
mineral
Banded Gneiss
Gneiss (Metamorphic rock predominantly containing quartz, feldspar, and mica)
metamorphic
Sandstone with Secondary Mineral Encrustation
Arenite with Silica/Calcite deposits (SiO2 or CaCO3)
sedimentary
Agate
Silicon dioxide (chalcedony), SiO2
sedimentary
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide inclusions
mineral
White Quartz Crystal Cluster
Silicon Dioxide (SiO2)
mineral
Polished Hematite Tower
Hematite (Fe2O3)
mineral
Amygdaloidal Basalt
Amygdaloidal Basalt
Igneous
Specular Hematite with Quartz and Limonite
Hematite (Fe2O3) with Quartz (SiO2) and Limonite (FeO(OH)·nH2O)
Mineral
Greenstone
Metabasalt / Chlorite Schist
metamorphic
Common Opal
Hydrated Amorphous Silica (SiO2·nH2O)
mineraloid
Limonite / Iron Oxide Concretion
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)
mineral
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
mineral
Polished blue-gray stone, likely labradorite or gneiss
Labradorite-bearing gneiss; plagioclase feldspar-rich rock
metamorphic
Diamond
Diamond (pure carbon, C)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Banded Gneiss
Gneiss (High-grade Metamorphic Rock)
metamorphic
Aventurine
Silicon Dioxide (SiO2) with inclusions
mineral
Copper-bearing Quartz Vein in Host Rock
Quartz with Malachite/Chrysocolla staining
igneous/metamorphic with mineral
Botryoidal Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
mineral
Dalmatian Stone
Dalmatian Jasper (a trade name for an igneous microcrystalline rock composed mostly of feldspar, quartz, and dravite)
igneous
Rhodochrosite
Manganese carbonate (MnCO3)
mineral
Weathered vesicular volcanic rock
Likely basaltic andesite or scoriaceous basalt; exact identification requires fresh surface and testing
igneous
Dalmation Stone (Dyed)
Peralkaline rhyolite
igneous