Quartz Geode (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
Category
Browse sedimentary rock (technically a variety of chalcedony) specimens identified by the Rock Identifier community.
Quartz Geode (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
Sandstone (likely Arkosic)
Arenite (SiO2 with KAlSi3O8)
Limestone (Weathered)
Calcium Carbonate (CaCO3)
Amygdaloidal Rhyolite
Amygdaloidal Rhyolite (Felsic volcanic rock)
Greenstone (Greenstone River Pebble)
Greenschist (metamorphosed mafic igneous rock)
Dendritic Opal (Common Opal)
Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
Sandstone (Ferruginous)
Arenite with Iron-Oxide Cement
Sandstone (Quartzose Sandstone)
Arenite (SiO2 principal component)
Muscovite Mica
Muscovite (Potassium Mica) KAl2(AlSi3O10)(OH)2
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Piddock-bored Mudstone
Lutite (Siltstone or Mudstone) with Pholad borings
Unidentifiable Rock Fragment
Milky Quartz
Silicon Dioxide (SiO2)
Apatite
Apatite group mineral (e.g., Fluorapatite - Ca5(PO4)3F, Chlorapatite - Ca5(PO4)3Cl, Hydroxylapatite - Ca5(PO4)3(OH))
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Limonite (Iron Ore)
Limonite (Hydrous iron(III) oxide-hydroxide mixture, primarily FeO(OH)·nH2O)
Veined Quartz
SiO2 (Silicon Dioxide)
Milky Quartz
Silicon Dioxide (SiO2)
Pyrite
Pyrite (Iron sulfide, FeS₂)
Pyrite
Iron Disulfide (FeS2)
Snakeskin Agate
Agate (Cryptocrystalline Quartz, SiO2)
Quartz (Milky/Clear variety)
Silicon Dioxide (SiO2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2)
Quartz (Quartzite fragment)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Conglomerate
Conglomerate (clastic sedimentary rock)
Tiger's Eye (Rough)
Pseudomorph of Quartz after Crocidolite (SiO2 with FeOOH inclusions)
Carnelian (Orange Chalcedony)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Chert (specifically Gray Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (often called Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Serpentine
Antigorite / Lizardite / Chrysotile (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
Quartz (Milky Quartz)
Quartz (SiO2 - Silicon Dioxide)
Sandstone
Arenite (SiO2 primarily)
Agate
Silicon Dioxide (SiO2)
Serpentine
Antigorite, Lizardite, or Chrysotile (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
Chert (Yellow variety / Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Aquamarine and clear quartz
Aquamarine (Be3Al2Si6O18), Quartz (SiO2)