Flint
Sedimentary cryptocrystalline quartz (SiO2)
Category
Browse mineral (specifically, a variety of the mineral species pyrope almandine garnet) specimens identified by the Rock Identifier community.
Flint
Sedimentary cryptocrystalline quartz (SiO2)
Epidosite with Quartz (Unakite-variant or Jasper)
Epidotized Metasomatite
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Schist
Mica Schist
Banded Agate (specifically Sardonyx)
Silicon Dioxide (SiO2) - variety of Chalcedony/Quartz
Chalcedony (specifically Agate or Carnelian variety)
Cryptocrystalline Silica (SiO2)
Leopard Skin Jasper
Chalcedony (cryptocrystalline Quartz)
Gastly (Trick or Trade Halloween Series)
Cellulose-carbonaceous composite (Lignocellulose laminated with pigmentary polymers)
Sandstone (likely Graywacke or Siltstone variety)
Clastic Sedimentary Rock (SiO2 with assorted mineral fragments)
Granite
Granitoid (comprised of Quartz, Feldspar, and Mica)
Schist
Mica Schist (Quartz-Muscovite-Biotite Schist)
Bumblebee Jasper
Anhydrite with Sulfur, Hematite, and Orpiment (SiO2/CaSO4 mixture)
Quartz-rich breccia or altered granite fragment
Polymineralic quartz–feldspar rock, likely hydrothermally altered granite/pegmatite
Coarse-grained Quartz and Feldspar Pegmatite
Pegmatite (Quartz: SiO2, Feldspar: KAlSi3O8)
Mica Schist
Mica Schist (primarily Muscovite or Biotite KAl2(AlSi3O10)(OH)2)
Schist
Mica Schist
Jasper (specifically Fancy or Polychrome Jasper)
Silicon Dioxide (SiO2) - Chalcedony
Petrified Wood
Silicified Wood (primarily SiO2)
Amethyst Lace Agate / Banded Amethyst
Silicon Dioxide (SiO2) with Fe3+ impurities
Fossil shell fragment (likely brachiopod or bivalve)
Indeterminate fossilized carbonate shell; likely Brachiopoda or Bivalvia
Granite (White Granite variant)
Phaneritic Plutonic Rock (High-silica Felsic)
Weathered iron-rich rock, likely limonite/goethite-bearing laterite
Limonite–goethite aggregate, commonly approximated as hydrated iron oxides (FeO(OH)·nH₂O)
Emerald in Matrix
Beryl (Be3Al2Si6O18)
Chalcedony (specifically Agate and Carnelian variety)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Schist
Mica Schist
Chert (specifically Tan Chert)
Chert (SiO2)
Jasper (Green Jasper/Chert)
Silicon Dioxide (SiO2)
Agate (specifically Carnelian or Honey Agate)
Silicon Dioxide (SiO2)
Black Tourmaline (Schorl)
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
Serpentine
Serpentinite (group of hydrous magnesium iron phyllosilicate minerals, e.g., Lizardite, Antigorite)
Schist
Crystalline Schist (often containing Muscovite, Biotte, or Quartz)
Fuchsite
Cr-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)
Travertine (Tufa)
Calcium Carbonate (CaCO3)
Biotite Schist
Biotite-rich Schist [K(Mg,Fe)3AlSi3O10(F,OH)2]
Quartz (Citrine)
Silicon Dioxide (SiO2)
Schist
Schist (Crystalline Metamorphic Rock)
Gneiss (specifically a Granitic Gneiss)
Gneiss (Composition: Quartz, Feldspar, Mica)
Jasper
Jasper (Silicon Dioxide, SiO2 with iron inclusions)
Schist
Schist
Granite / Gneiss Ballast Rock
Granite (Quartzo-feldspathic rock)
Likely weathered iron-rich rock or mineral fragment
Indeterminate; possibly limonite/goethite-rich material with quartz or feldspar