Chalcedony (River Agate)
Silicon Dioxide (SiO2)
Category
Browse amorphous solid specimens identified by the Rock Identifier community.
Chalcedony (River Agate)
Silicon Dioxide (SiO2)
Geode Nodules / Agate Chert
Silicon Dioxide (SiO2)
Geode or Concretion
Silica-rich Concretion or Unopened Geode (SiO2)
Native Gold Nugget
Native Gold (Au)
Quartzite
Quartzite (chiefly SiO2)
Agate Geode (Unopened)
Cryptocrystalline Quartz (SiO2) with Chalcedony
Quartz Geode
Silicon Dioxide (SiO2)
Quartz Geode
Quartz (Silicon Dioxide, SiO2) Geode
Gold Ore / Native Gold
Native Gold (Au)
Chondrite Meteorite
Ordinary Chondrite (S-type asteroid origin)
Basalt with Amygdules
Amygdaloidal Basalt
Quartz Geode
Silicon Dioxide (SiO2) in a concretion
Polished green-inclusion stone, likely chlorite-included quartz
Quartz (SiO₂) with chlorite inclusions; exact identification is uncertain from the photograph
Black Onyx
Silicon dioxide / Chalcedony (SiO2)
Quartz Geode (Unbroken)
Silicon Dioxide (SiO2)
Peach Aventurine
Quartz variety (SiO2 + Hematite/Goethite inclusions)
Porphyritic Andesite
Andesite (Porphyritic texture)
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
Quartz Geode
Silicon Dioxide (SiO2)
Quartzite Cobble
Quartzite (SiO2)
Quartzite Pebble
Quartzite
Chalcedony (Yellow Jasper or Agate)
Microcrystalline Quartz (SiO2)
Quartz-Veined Gneiss or Metamorphic Rock with Quartz Veins
Quartz-veined metamorphic rock (Silicate mineral assemblage)
Sulfur (with possible Cullet Glass or Slag imitation)
Native Sulfur (S8)
Gold
Native Gold (Au)
Gold
Native Gold (Au)
Orbicular Jasper (Ocean Jasper variant)
Silicon Dioxide (SiO2) with iron oxide inclusions
Quartz Geode
Silicon Dioxide (SiO2)
Quartzite Pebble
Quartzite
Vesicular Basalt (Scoria)
Aphanitic Mafic Igneous Rock (Vesicular Basalt)
Geode (Quartz / Chalcedony Geode)
SiO2 (Silicon Dioxide)
Turquoise
Hydrated phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O
Petrified Wood
Silicified Wood (SiO2)
Green Quartzite
Silicon Dioxide (SiO2) with mineral inclusions
Quartzite
Metamorphic Quartzite (SiO2)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony replacing $SiO_2$)
Ferruginous Quartzite (Iron-stained Quartz)
Quartzite (SiO2 with Fe-oxide staining)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Graphic Granite
Graphic Granite (Granite Pegmatite)
Geode (unopened) or Calcareous Nodule
Siliceous or Calcareous Concretion/Nodule
Quartzite Breccia
Brecciated Quartzite (SiO2)
Amethyst Geode
Silicon Dioxide with trace inclusions of Iron (SiO2)