Chert (variations include Flint)
Chert (Silicon Dioxide, SiO2)
Category
Browse organic material (likely a fruit or berry) specimens identified by the Rock Identifier community.
Chert (variations include Flint)
Chert (Silicon Dioxide, SiO2)
Chert (Flint)
Microcrystalline silica (SiO2)
Chert (Common Opal/Jasper variety)
Cryptocrystalline Quartz (SiO2)
Granitic Quartz with Feldspar
Granite (composed primarily of SiO2 and KAlSi3O8)
Quartzite River Stone
Metamorphosed Quartz-rich Sandstone (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline silicon dioxide (SiO2)
Iron-stained quartz-rich rock, possibly jasper/quartzite
Quartz (SiO₂) with iron-oxide staining; likely ferruginous quartzite or jasper
Smoky quartz (likely)
Quartz, silicon dioxide (SiO₂), naturally irradiated variety
Sandstone (Quartzose Sandstone)
Arenite (primarily SiO2)
Banded gneiss pebble
Gneiss, commonly quartz–feldspar–mica gneiss
Coal
Anthracite / Bituminous Coal
Limestone (likely weathered)
Limestone (Mainly Calcium Carbonate, CaCO3)
Tumbled cream-colored stone, likely quartzite or limestone
Probably quartzite (microcrystalline SiO₂); limestone alternative: calcite (CaCO₃)
Red Granite
Phaneritic Felsic Igneous Rock
Tumbled brown jasper
Microcrystalline quartz/chalcedony (SiO₂), commonly iron-oxide stained
Petrified Wood
Silicified Wood (SiO2)
Fossilized Shark Tooth
Chondrichthyes (Class)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
Petrified Wood
Silicified Wood (SiO2)
Jasper
Jasper (Silicon Dioxide) - SiO2
Petrified Wood
Silicified wood (Quartz, SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Petrified Wood
Silicified Wood (primarily SiO₂)
Rounded dark river pebble
Likely fine-grained basalt or andesite; exact identification requires a fresh surface or tests
Petrified Wood
Silicified Wood (SiO2)
Fossilized Shark Tooth
Chondrichthyes (Class)
Red Sandstone
Arenite (Iron-rich Sandstone)
Chert (Septarian or Nodular variety)
Microcrystalline Quartz (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (often called Flint in various colors)
Silicon Dioxide (SiO2)
Chert (varietal Chalcedony or Flint)
Silicon dioxide (SiO2) - Microcrystalline Quartz
Chert Arrowhead
Microcrystalline Quartz (SiO2)
Moss Agate
Silicon Dioxide (SiO2) with inclusions
Chert (or Chalcedony) Nodule
Microcrystalline Quartz (SiO2)
Chalcedony (Agate)
Silicon Dioxide (SiO2)
Chert (often associated with Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Fossilized coral or carbonate fossil fragment
Calcareous fossil, likely colonial coral (order Hexacorallia; uncertain from image)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Tumbled pegmatitic granite
Coarse-grained granite/pegmatite, chiefly quartz, feldspar, and biotite or amphibole