Emerald in Matrix
Beryl (Be3Al2Si6O18)
mineral
Category
Mineralogical Specimen
Browse mineralogical specimen specimens identified by the Rock Identifier community.
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Druzy Quartz on Matrix (Chert/Limestone)
Silicon Dioxide (SiO2) with Carbonate host rock
sedimentary
Druzy Quartz on Matrix (likely Limestone or Sandstone)
Silicon Dioxide (SiO2) with various trace impurities
Mineral on Sedimentary Rock
Agate
Silicon dioxide (SiO2) - variety Chalcedony
mineral
Citrine Quartz
Silicon Dioxide (SiO2)
mineral
Tumbled yellow-green stone, possibly serpentine
Likely serpentine-group mineral (Mg₃Si₂O₅(OH)₄); exact identification requires testing
mineral
Banded Serpentinite with Calcite Veins
Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
metamorphic
Quartz (Raw Chunk)
Silicon Dioxide (SiO2)
mineral
Milky quartz-bearing rock
Quartz, silicon dioxide (SiO₂), likely massive milky quartz in a host rock
mineral
Quartz geode fragment
Microcrystalline and drusy quartz, SiO₂, likely in a weathered carbonate or volcanic host
mineral
Chert (Vuggy or Chalcedony)
Cryptocrystalline Quartz (SiO2)
sedimentary
Quartz Druzy in Brecciated Matrix
Silicon Dioxide (SiO2) in Lithic Breccia
sedimentary
Pyrite
Iron Sulfide (FeS2)
mineral
Unidentified light-colored rock or mineral specimen
Indeterminate; possibly weathered calcite-rich material, limestone, or pale quartz-bearing rock
mineral
Peridot (Olivine)
Magnesium Iron Silicate (Mg, Fe)2SiO4
mineral
Chert (Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Quartz with Schist Matrix
Crystalline Silicon Dioxide (SiO2) in micaceous schist
metamorphic
Granite Pegmatite
Phaneritic Plutonic Igneous Rock
igneous
Smoky quartz (likely)
Quartz, silicon dioxide (SiO₂)
mineral
Quartz Crystal (Smoky Quartz)
Silicon Dioxide (SiO2)
mineral
Quartz Geode
Crystalline Silica (SiO2)
mineral
Quartz Cluster (Likely Ferruginous)
Silicon Dioxide (SiO2)
mineral
Quartz–feldspar pegmatite with pink tourmaline
Granitic pegmatite; predominantly quartz (SiO₂), microcline/orthoclase (KAlSi₃O₈), albite (NaAlSi₃O₈), and likely elbaite tourmaline (Na(Li,Al)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
igneous
Snowflake Obsidian
Volcanic Glass with Spherulite Inclusions (70-75% SiO2)
igneous
Quartz Geode Fragment
Silicon Dioxide (SiO2)
mineral
Red Jasper (Chert)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Druzy Quartz on Agate/Chert
Silicon Dioxide (SiO2)
mineral
Galena with Pyrite on Matrix
Lead(II) sulfide (PbS) with Iron disulfide (FeS2)
mineral
Yellow Agate (Chalcedony)
Silicon Dioxide (SiO2)
mineral
Rock crystal (clear quartz), likely rough or lightly polished
Quartz — silicon dioxide (SiO₂)
mineral
Weathered iron-rich volcanic rock (probable basalt or andesite)
Altered basalt/andesite, composed chiefly of plagioclase, pyroxene, and iron oxides/hydroxides
igneous
Likely weathered iron-rich pebble (brown sandstone or ironstone)
Indeterminate ferruginous sandstone/ironstone; commonly quartz (SiO₂) with iron oxides such as goethite and hematite
sedimentary
Gold-bearing quartz vein rock
Quartz (SiO₂) with probable native gold and iron-oxide minerals
mineral
Brecciated quartz vein rock
Quartz (SiO₂), with iron-oxide staining and likely feldspar/carbonate gangue
mineral
Fossiliferous limestone with possible ammonite or shell impressions
Calcitic limestone, chiefly CaCO₃; fossils may include ammonoids or bivalves
fossil
Vein-filled Sedimentary Rock
Silicified sedimentary rock with quartz/calcite vein
sedimentary
Mixed Rock and Mineral Collection
Various geological specimens
igneous, sedimentary, and metamorphic
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily SiO2 with Fe2O3)
sedimentary
Quartz with Iron Staining
Silicon Dioxide (SiO2)
mineral
Pyrite
Iron Pyrite (FeS2)
mineral
River Rock (likely Gneiss or Quartzite)
Metamorphic rock specimen (potentially Foliated Gneiss)
metamorphic
Milky Quartz with Iron Inclusions
Silicon Dioxide (SiO2)
mineral