Banded Agate (specifically Carnelian Agate)
Silicon dioxide (SiO2) - Chalcedony variety
mineral
Category
Mineral Based Human Made Alloy
Browse mineral based human made alloy specimens identified by the Rock Identifier community.
Granite
Phaneritic plutonic felsic rock (primarily Quartz, Feldspar, and Mica)
igneous
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (specifically Yellow/Honey Jasper variety)
Cryptocrystalline Quartz (SiO2)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Slag (Industrial Byproduct)
Ferro-silicate glass (Slag)
Anthropogenic (Man-made industrial deposit)
Scoria (Lava Rock)
Mafic extrusive volcanic rock (Scientific formula varies based on mineral content: primarily SiO2, MgO, and FeO)
igneous
Basalt with vesicles/amygdules
Basalt (containing volcanic glass and plagioclase)
igneous
Chalcedony (specifically Blue Chalcedony or Common Opal variety)
Silicon Dioxide (SiO₂)
mineral
Man-made Synthetic Material (Plastic/Composite)
Acrylonitrile Butadiene Styrene (ABS) or High-Impact Polystyrene (HIPS)
Non-geological / Synthetic
Tree Agate
Silica (SiO2) with Chlorite inclusions
mineral
Red Ochre (Hematite-rich Clay)
Limonitic/Hematitic Claystone (Fe2O3 with clay minerals)
Sedimentary
Sandstone
Arenite (SiO2 based)
sedimentary
Iron-Nickel Meteorite fragment
Siderite (meteoritic iron), composed primarily of Kamacite (α-(Fe,Ni)) and Taenite (γ-(Fe,Ni))
mineral
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (and/or Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Chert (specifically Flint or Jasper variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Flint nodule)
Silicon dioxide (SiO2)
sedimentary
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Chert (with Iron Staining)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Sandstone
Arenite (SiO2 principal)
sedimentary
Schist
Schist (primarily mica-schist)
metamorphic
Schist
Mica Schist (predominantly Muscovite/Biotite)
metamorphic
Rose Quartz (likely carved)
Rose Quartz (SiO2)
Mineral
Granite
Phaneritic high-silica plutonic rock (composed primarily of Quartz, Feldspar, and Mica)
igneous
Jasper
Silicon dioxide (SiO2) with iron oxide inclusions
sedimentary
Ferruginous Sandstone (with possible Epidote/Chlorite coloring)
Sandstone (SiO2 dominated with Fe2O3 staining)
sedimentary
Schist
Mica Schist (primarily Muscovite and Biotite)
metamorphic
Sandstone
Arenite (SiO2 based)
sedimentary
Pearl
Calcium Carbonate (Aragonite) with Conchiolin; formula: CaCO3
mineral
Potassium-Rich Silicate Clay (inferred from biological context)
Phyllosilicate group (likely Illite or Smectite within surrounding soil substrate)
mineral
Muscovite Mica (Granitic Pegmatite)
Muscovite - KAl2(AlSi3O10)(OH)2
igneous
Chert (and Jasper/Flint variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Mosasaur Tooth Fossil
Mosasaurid vertebrate fossil (Hydroxyapatite)
mineral
Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
mineral
Mica Schist
Crystalline Schist (often containing Muscovite, Biotite, and Quartz)
metamorphic
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Volcanic Rock)
Igneous
Sandstone (Quartzite-rich)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Sandstone (likely Quartzose Sandstone)
Arenite (primarily SiO2)
sedimentary
Sandstone (Ferruginous)
Sandstone (primarily SiO2 with Iron Oxide cement)
sedimentary
Fuchsite (Chrome Mica)
K(Al,Cr)2(AlSi3O10)(OH)2
mineral
Citrine Quartz
Silicon Dioxide (SiO2)
mineral