Basalt with Quartz Vein
Mafic volcanic rock with hydrothermal SiO2 filling
igneous
Category
Mineral Precipitate (Anthropogenic Context)
Browse mineral precipitate (anthropogenic context) specimens identified by the Rock Identifier community.
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Amethyst on Agate/Basalt Matrix
Silicon Dioxide (SiO2) with iron impurities
mineral
Quartz Geode
Silicon Dioxide (SiO2) within a geode
mineral
Quartz Geode
Crystalline Silicon Dioxide (SiO2) in a Geode
mineral
Agate (Geode nodule)
Cryptocrystalline Quartz (SiO2)
mineral
Quartz (Milky or Cloudy Quartz)
Quartz (Silicon Dioxide, SiO2)
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Chert (with Quartz vein/coating)
Microcrystalline Quartz (SiO2)
sedimentary
Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Milky Quartz with Iron Oxide
Quartz (Silicon Dioxide, SiO2) with Limonite/Goethite staining
mineral
Quartz (possibly milky quartz or quartz with inclusions)
SiO2 (Silicon Dioxide)
Mineral
Quartz Druzy (Geode Fragment)
Silicon Dioxide (SiO2)
mineral
Quartz Geode (Nodule)
Silicon Dioxide (SiO2)
sedimentary or igneous
Sandstone with Concretions / Liesegang Rings
Arenite with iron oxide banding
sedimentary
Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx')
Calcite (Calcium Carbonate, CaCO3)
sedimentary
Coquina
Biogenic Limestone (Coquina)
sedimentary
Banded Iron Formation (BIF)
Banded Iron Formation (predominantly Hematite Fe2O3 and magnetite Fe3O4 alternating with Chert SiO2)
sedimentary
Basalt with Quartz Veins
Aphanitic Mafic Igneous Rock (primarily Plagioclase and Pyroxene) with SiO2 inclusions
igneous
Ferruginous Sandstone
Arenite with Iron-Oxide Cement (SiO2 with Fe2O3/FeO(OH))
sedimentary
Septarian Nodule (Thunder Egg variant)
Septarian concretion (Calcite, Aragonite, and Limestone)
sedimentary
Amygdaloidal Basalt with Quartz/Calcite Inclusions
Amygdaloidal Basalt (SiO2 / CaCO3 inclusions)
igneous
Moqui Marble
Iron Oxide Concretion (Limonite/Hematite over Sandstone)
sedimentary
Black Onyx
Silicon Dioxide (SiO2) with parallel banding
mineral
Oolitic Limestone
Oolitic Limestone (CaCO3)
sedimentary
Basalt with Quartz Veins
Aphanitic Mafic Igneous Rock (Main body: SiO2, Fe, Mg rich)
igneous
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint)
Chert (Cryptocrystalline Quartz, SiO2)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Dendritic Agate (Tumbled)
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
mineral
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Quartz with Chlorite or Hornblende inclusions
Silicon dioxide (SiO2) with phyllosilicate or amphibole inclusions
metamorphic
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Agate (Puddingstone style)
Silicon Dioxide (SiO2) with impurities
mineral
Green Calcite
Calcite (Calcium Carbonate, CaCO3)
mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Amethyst Geode
Crystalline Quartz (SiO2) with iron impurities
mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Chalcedony (Botryoidal/Drusy Quartz)
Silicon Dioxide (SiO₂)
Mineral
Aragonite
Aragonite (Calcium Carbonate - CaCO3)
mineral