Red Agate
Agate (Cryptocrystalline variety of Quartz, SiO2)
mineral
Category
Mineral Precipitate (Anthropogenic Context)
Browse mineral precipitate (anthropogenic context) specimens identified by the Rock Identifier community.
Learn about Mineral Precipitate (Anthropogenic Context) in the encyclopedia
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Banded Agate (Dyed Purple)
Agate (Variety of Chalcedony/Quartz), SiO2
mineral
Orbicular Jasper (Ocean Jasper)
Silicon Dioxide (SiO2) with iron and magnesium inclusions
mineral
Blue Goldstone
Synthetic glass with cobalt and copper inclusions
man-made glass
Limonite (Ironstone)
Hydrated Iron(III) Oxide-hydroxide (FeO(OH)·nH2O)
sedimentary
Carnelian Agate Beads
Silicon Dioxide (SiO2)
gemstone
Quartz Geode Pebble
Silicon Dioxide (SiO2)
sedimentary
Quartz Druze on Matrix
Silicon Dioxide (SiO2)
mineral
Agate (specifically Waterline or Onyx-type Agate)
Silicon Dioxide (SiO2) - variety Chalcedony
mineral
Tufa (Calcareous Tufa)
Calcareous Tufa (Precipitated CaCO3)
sedimentary
Quartz Vein in Matrix (Gneiss/Schist)
Silicon Dioxide (SiO2) in Metamorphic Rock Matrix
metamorphic
Chert (Iron-stained)
Silicon Dioxide (SiO2)
sedimentary
Onyx Marble (Banded Calcite)
Calcite (Calcium Carbonate, CaCO3)
sedimentary
Greywacke with Quartz Veins
Lithic Sandstone (Greywacke) with SiO2 inclusions
sedimentary
Dendritic Limestone
Calcite with Manganese Oxide (Manganese Dendrites)
sedimentary
Potassium-Rich Silicate Clay (inferred from biological context)
Phyllosilicate group (likely Illite or Smectite within surrounding soil substrate)
mineral
Agate and Amethyst (Quartz variants)
Silicon Dioxide (SiO2) - Microcrystalline Quartz and Crystalline Quartz
mineral
Celestite Geode
Celestine (Strontium Sulfate, SrSO4)
mineral
Pyrite in Quartz
Iron Sulfide (FeS2) in Silicon Dioxide (SiO2)
mineral
Purple fluorite specimen
Fluorite (calcium fluoride, CaF₂)
mineral
Carnelian
Silicon Dioxide (Quartz variety, SiO2)
mineral
Chrysocolla
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4·nH2O
mineral
Geode (Calcite or Quartz)
Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3)
sedimentary
Chrysocolla
Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4 · nH2O)
mineral
Blue calcite cluster
Calcite (calcium carbonate, CaCO₃)
mineral
Blue calcite (probable)
Calcite — CaCO₃
mineral
Blue calcite (probable)
Calcite, calcium carbonate (CaCO₃)
mineral
Carnelian
Silicon Dioxide (SiO2) - variety of Chalcedony
mineral
Desert Rose (Gypsum Variety)
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
mineral
Quartz Crystal
Silicon Dioxide (SiO2)
mineral
Quartz Geode
Silicon Dioxide (SiO2) in Geodic Cavity
sedimentary
Fluorite
Calcium Fluoride (CaF2)
mineral
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Red Jasper (River Pebble)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary/mineral
Banded Quartz with Host Rock / Quartz Vein Pebble
Silicon Dioxide (SiO2) in Metamorphic Matrix
metamorphic
Fluorite (often referred to casually as 'Fluorspar' in industrial contexts)
Fluorite (CaF2)
Mineral
Vesicular Basalt
Amygdaloidal Basalt (Mafic extrusive volcanic rock)
Igneous
Concrete
Anthropogenic Sedimentary Conglomerate (Cement mixture: typically Ca2SiO4, Ca3SiO5, Ca3Al2O6)
sedimentary (artificial)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
mineral
Pink Zebra Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Chert / Jasper
Silicon Dioxide (SiO2)
sedimentary
Chert (Jasper/Chalcedony)
Microcrystalline Quartz (SiO2)
sedimentary