Dragon Vein Agate (Dyed/Treated)
Agate (SiO2)
mineral
Category
Mineral (Silicate Replaced Organic Material)
Browse mineral (silicate replaced organic material) specimens identified by the Rock Identifier community.
Learn about Mineral (Silicate Replaced Organic Material) in the encyclopedia
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Chert (Flint Nodular)
Chert (Silicon dioxide, SiO2)
sedimentary
Chert (often referred to as Flint)
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Schist
Mica Schist (primarily Muscovite or Biotite sheet silicates)
metamorphic
Limestone (Concretionary or Tufa)
Calcium Carbonate (CaCO3)
sedimentary
Garden Quartz
Included Quartz (SiO2 with accessory minerals such as Chlorite, Hematite, or Feldspar)
mineral
Chert (River Siltstone/Flint)
Chert (SiO2)
sedimentary
Precious Red Coral
Corallium rubrum / Corallium japonicum
mineral (organic gemstone)
Sandstone
Arenite (SiO2 principal)
sedimentary
Sandstone
Arenite (SiO2 based)
sedimentary
Bauxite
Bauxite (Mixture of Al(OH)3, AlO(OH), and Fe2O3)
sedimentary
Sandstone (Ferruginous)
Arenite with Iron Oxide staining (Fe2O3)
sedimentary
Sandstone
Arenite (primarily composed of SiO2 - Silicon Dioxide)
sedimentary
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
mineral
Chiastolite (Andalusite)
Al2SiO5
metamorphic
Concrete
Hydrated Portland Cement Aggregate Composite
Anthropogenic Sedimentary (Man-made)
Red Sandstone
Arenite (primarily Quartz with Iron Oxide coating)
sedimentary
Ferruginous Sandstone (Ironstone)
Clastic sedimentary rock (SiO2 with Fe2O3/FeO(OH) cement)
sedimentary
Sandstone
Arenite (Clastic Sedimentary Rock)
sedimentary
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
mineral
Sulfidic Mudstone with Pyrite/Goethite
Sulfidic Siltstone/Mudstone (FeS2)
sedimentary
Fossilized Crinoid Stem Segment
Crinoid (Phylum Echinodermata, Class Crinoidea)
sedimentary
Coal (most likely Bituminous or Anthracite)
Bituminous Coal (Grade of Coal), Anthracite (Grade of Coal)
Sedimentary Rock
Chert (or Flint)
Chert (Sedimentary Cryptocrystalline Sio2)
sedimentary
Sandstone (Banded)
Arenite
sedimentary
Yellow Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Milky Quartz with Mica inclusions
Quartz (Silicon Dioxide, SiO2)
mineral
Sandstone (Banded)
Clastic Sedimentary Rock: Arenite
sedimentary
Siltstone
Siltstone (composed of microscopic quartz and clay minerals)
sedimentary
Diamond (or Cubic Zirconia simulant)
Carbon (C) or Zirconium Dioxide (ZrO2)
mineral
Tiger's Eye (Polished Point/Tower)
SiO2 (Silicon Dioxide) with included crocidolite fibers
Mineral (Metamorphic pseudomorph)
Pyrite in Shale
Iron Sulfide (FeS2) in Sedimentary Matrix
mineral
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Mother of Pearl (Nacre)
Nacre (Aragonite/Conchiolin), CaCO3 + Organic Polymers
mineral
Pearl
Calcium Carbonate (Aragonite/Calcite mixed with Conchiolin), CaCO3
mineral
Gneiss (specifically Biotite Gneiss)
Gneiss (high-grade metamorphic rock primarily composed of Silicates)
metamorphic
Opalite (a synthetic glass)
Silicon Dioxide (SiO2) with various additives; not a true mineral but a man-made gem simulant
Mineral Simulant (Synthetic Glass)
Milky Quartz/Gray Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Sugilite
Sugilite (KNa2(Fe,Mn,Al)2Li3Si12O30)
mineral