Quartz
Quartz (SiO2 - Silicon Dioxide)
Mineral
Category
Sedimentary Rock (Technically A Variety Of Chalcedony)
Browse sedimentary rock (technically a variety of chalcedony) specimens identified by the Rock Identifier community.
Travertine (Calcareous Tufa)
Calcium Carbonate (CaCO3)
sedimentary
Dyed Agate
Silicon Dioxide (SiO2) with artificial pigment
mineral
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide
mineral
Jasper (Green/Yellow Moss Jasper)
Silicon Dioxide (SiO2)
mineral
Banded Agate (Onyx variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
mineral
Jasper in Basalt Matrix
Silicon Dioxide (SiO2) with impurities; Chalcedony
sedimentary (secondary mineral) within igneous
Shale
Lutaceous sedimentary rock
sedimentary
Red Quartz (Carnelian/Red Jasper Agate)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
mineral
Dalmatian Stone
Dalmatian Stone (a peralkaline igneous rock consisting of Feldspar, Quartz, and Arfvedsonite)
igneous
Sandstone (Quartzose Sandstone)
Arenite
sedimentary
Marble
Recrystallized Calcite (CaCO3) Rock
metamorphic
Chert (Jasper variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Amethyst
Quartz variety; chemical formula: SiO₂ (silicon dioxide) with Fe³⁺ impurities
Mineral
Ironstone Concretion / Goethite-Hematite Nodule
Goethite/Hematite (α-FeO(OH) / Fe2O3)
sedimentary
Chert (specifically Green Chert/Jasper)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
sedimentary
River Pebble (Likely Quartzite or Chalcedony)
Silicon Dioxide (SiO2) - granular metamorphic variety
metamorphic
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Tiger's Eye
Tiger's Eye (a variety of Chalcedony, which is a microcrystalline quartz with fibrous inclusions of oxidized crocidolite)
Mineral
Mookaite Jasper
Radiolarite (Silica, SiO2)
sedimentary
Fire Agate
Silicon Dioxide (SiO2) with layers of Limonite/Goethite
mineral
Chert (or Flint)
Chert (a cryptocrystalline variety of quartz, SiO2)
sedimentary
Obsidian
Obsidian (Amorphous volcanic glass, SiO2 rich)
igneous
Chert (Red/Brown Variety)
Microcrystalline quartz (SiO2)
sedimentary
Blue Lace Agate (with Amethyst Geode center)
Silicon Dioxide (SiO2) - Cryptocrystalline Chalcedony
mineral
Sandstone (likely Siltstone or Mudstone variety)
Clastic Sedimentary Rock (primarily SiO2 with iron oxides)
sedimentary
Quartz
Quartz (SiO₂)
Mineral
Granite
Granite (a broadly defined plutonic igneous rock, often more specifically classified as quartz monzonite or granodiorite based on precise mineral percentages)
igneous
Sandstone (Ferruginous)
Arenite with Iron Oxide cement (SiO2 + Fe2O3)
sedimentary
Obsidian
Volcanic Glass (comprised primarily of SiO2)
Igneous
Quartz (Milky/Crystal Variety)
Silicon Dioxide (SiO2)
mineral
Obsidian
Obsidian (principally SiO2 silicon dioxide)
igneous
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
sedimentary
Limestone (specifically Fossiliferous or Crinoidal Limestone)
Calcium Carbonate (CaCO3) - Calcite Rock
sedimentary
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
sedimentary
Limonitic Sandstone (Stained Sandstone)
Clastic Sedimentary Rock with Iron Oxide (Limonite/Goethite) staining
sedimentary
Agate
Cryptocrystalline Quartz (SiO2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Chert (Flint Nodules)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Quartz
Quartz (SiO2 - Silicon Dioxide)
Mineral
Dragon Vein Agate
Chalcedony (Quartz) - SiO2
mineral
Ferruginous Sandstone
Arenite with Hematite/Limonite cement (SiO2 + Fe2O3)
sedimentary