Chert (Quartz Variety)
Chert (Silicon Dioxide, SiO2)
Category
Browse anthropogenic specimen (man made material) specimens identified by the Rock Identifier community.
Chert (Quartz Variety)
Chert (Silicon Dioxide, SiO2)
Sandstone (Micaceous/Feldspathic variant)
Arenite (specifically subarkose or lithic arenite)
Chert Pebble (Flint)
Microcrystalline/Cryptocrystalline Quartz (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Orange Quartzite (River Pebble)
Quartzite (primarily SiO2)
Pyrite
Iron Disulfide (FeS2)
Coquina
Biogenic Limestone (Calcium Carbonate, CaCO3)
Coquina / Fossiliferous Limestone
Calcite-rich Bioclastic Sedimentary Rock (CaCO3)
Sandstone with trace fossil
Sandstone, possibly with Skolithos or similar trace fossil
Slag (Industrial Glass Slag)
Amorphous Silica / Ferro-silicate Slag
Sandstone
Arenite (composed primarily of Quartz: SiO2)
Serpentine (Serpentinite)
Serpentinite (complex silicate group including lizardite, chrysotile, and antigorite)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Lepidolite on Pegmatite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
Siltstone
Siltstone (primarily composed of SiO2)
Red Swirl Beads (Likely Resin or Glass, simulating Red Jasper or Agate)
N/A (for the beads as pictured); Red Jasper: SiO2 (Chert variety); Red Agate: SiO2 (Chalcedony variety)
Rough Emerald
Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood (SiO2 - Silicon Dioxide)
Sandstone (Pebble)
Arenite (primarily SiO2)
Petrified Wood
Silicified Wood (primarily SiO₂ - Silicon Dioxide)
Jasper with Quartz Vein
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Granite Pebble (Pink Granite)
Phaneritic Igneous Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)
Red Jasper (River Siltstone)
Silicon Dioxide (SiO2) with iron oxide inclusions
Sandstone (with Iron Staining)
Arenite (composed primarily of SiO2 with Fe2O3 staining)
Green Aura Quartz (Titanium treated Kyanite or Quartz)
Silicon Dioxide (SiO2) or Aluminum Silicate (Al2SiO5) with Titanium/Metal Oxide coating
Granodiorite
Granodiorite (Quartz + Plagioclase + Alkali Feldspar + Biotite/Hornblende)
Chert (specifically Yellow Jasper variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Metallic Ornament / Jewelry
N/A - This is an artificial object, not a geological specimen.
Obsidian (Black)
Obsidian (High-silica volcanic glass)
Agate (specifically, multi-colored or pastel-dyed agate)
Silicon dioxide (SiO2) - specifically, a cryptocrystalline variety of quartz known as Chalcedony, with banding classified as Agate. (If it were Fluorite, the chemical formula would be Calcium Fluoride - CaF2).
Petrified Wood
Silicified Wood (SiO2)
Blue Chalcedony
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Chalk
Calcium Carbonate (CaCO3)
Quartz
Quartz (SiO₂ - Silicon Dioxide)
Limonite (Iron Ore/Sandstone mixture)
Limonite (FeO(OH)·nH2O) often mixed with Goethite and sedimentary matrix
Granite Cobble
Granite (Phaneritic igneous rock composed of Quartz, Feldspar, and Mica)
Chert (often called Flint)
Chert (Microcrystalline or cryptocrystalline Silica, SiO2)
Nuummite
Nuummite (intergrowth of orthoamphiboles Anthophyllite and Gedrite, (Mg,Fe)7Si8O22(OH)2)
Diorite
Phaneritic Intrusive Igneous Rock (composed of Plagioclase feldspar, Hornblende, and Biotite)
Banded Iron Formation (BIF) with Quartz
Banded Iron Formation, often composed of alternating layers of hematite (Fe2O3) or magnetite (Fe3O4) and chert (microcrystalline quartz, SiO2)