Chert (Iron-rich variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Category
Browse organic structure (not a rock) specimens identified by the Rock Identifier community.
Chert (Iron-rich variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chalcedony (Botryoidal or Tumbled)
Chalcedony (SiO₂)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Brachiopod Fossil (Spiriferid)
Order Spiriferida (Phylum Brachiopoda); mineralized as Calcite (CaCO3) or Chert (SiO2)
Quartz Vein in Amphibolite / Gneiss
Quartz (SiO2) in Mafic Metamorphic Host Rock
Granite
Phaneritic plutonic rock (primarily Quartz, Feldspar, and Mica)
Red Jasper
Microcrystalline Quartz (Chalcedony), SiO2 with iron oxide inclusions
Chert (Jasper variety)
Microcrystalline Quartz (SiO2)
Chert (specifically Jasper or Flint variant)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified wood (primarily SiO2)
Limestone (or Sandstone)
Calcium Carbonate (CaCO3) / Silica (SiO2)
Coal (most likely Bituminous or Anthracite)
Bituminous Coal (Grade of Coal), Anthracite (Grade of Coal)
Fossil Brachiopod or Mollusk Cast
Phylum Brachiopoda / Mollusca internal mold
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Yellow Jasper
Silicon Dioxide (SiO2)
Chert (Flint)
Silicon dioxide (SiO2)
Ironstone Concretion
Siderite or Goethite Concretion
Chert Arrowhead (Jasper)
Chert (Cryptocrystalline Quartz, SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Jasper
Silicon Dioxide (Microcrystalline Quartz, SiO2)
Moss Agate
Silicon Dioxide (SiO2) with Manganese or Iron Oxide inclusions
Chert Pebble
Microcrystalline Quartz (SiO2)
Chert (potentially worked flint)
Cryptocrystalline microcrystalline quartz (SiO2)
Chert (River Pebble)
Microcrystalline silica (SiO2)
Chert (Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Dragon Blood Jasper
Epidote with Red Piedmontite (Chalcedony/Quartz variant)
Green Jasper
Silicon Dioxide (SiO2) with impurities of iron(II) silicate
Chert (Fossiliferous Chert/Flint)
Silicon Dioxide (SiO2)
Sandstone with Desert Varnish
Arenite (SiO2 predominantly) with Ferromanganese coating
Moss Agate
Silicon Dioxide with inclusions (SiO2 + impurities)
Amber in Matrix
Succinite (Carbon-based organic polymer)
Jasper
Silicon Dioxide (SiO2) with impurities
Chert (Jasper/Flint variety)
Microcrystalline quartz (SiO2)
Fairy Stone (Menilite Concretion)
Carbonate-rich concretion (often Siderite or Calcite in Clay)
Chert (Brown Variety)
Microcrystalline quartz (SiO2)
Jasper
Silicon dioxide (SiO2)
Sandstone
Quartz Sandstone (predominantly)
Banded Chert
Silicon Dioxide (SiO2)
Chert (River Pebble)
Microcrystalline Silica (SiO2)
Chert
Chert (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert Pebble
Microcrystalline Quartz (SiO2)