Rounded gray pebble, likely basalt or andesite
Fine-grained volcanic rock, probably basaltic-andesite; exact identification requires testing
Category
Browse organic material (likely a fruit or berry) specimens identified by the Rock Identifier community.
Rounded gray pebble, likely basalt or andesite
Fine-grained volcanic rock, probably basaltic-andesite; exact identification requires testing
Fossiliferous Limestone
Biogenic Limestone (CaCO3)
Sandstone (with Manganese staining)
Arenite (composed primarily of SiO2)
Chert (and Jasper/Flint variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (potentially Jasper/Common Opal mixture)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Limestone with Iron Oxide Staining
Sedimentary Rock (Calcite, CaCO3)
Chert / Flint
Silicon Dioxide (SiO2)
Chert (Yellow Jasper/Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Petrified Wood
Silicified Wood (primarily SiO2)
Yellow Chert
Chert (Cryptocrystalline Quartz, SiO2)
Vesicular basalt (likely scoria)
Mafic volcanic rock; predominantly plagioclase, pyroxene, and volcanic glass, with possible olivine
Chert (River Stone)
Microcrystalline Quartz (SiO2)
Not a geological specimen
N/A (man-made object)
Petrified Wood
Silicified Wood (SiO2)
Weathered granite or granitic gneiss
Granite; predominantly quartz, feldspar, and mica, possibly altered to gneiss
Sandstone River Cobble
Arenite (SiO2 based)
Iron Slag
Ferrous Slag (Industrial Byproduct)
Sandstone
Clastic sedimentary rock (primarily Quartz and Feldspar)
Basalt with Mineral Vein (Cobble)
Basalt (with likely Quartz/Calcite vein)
Sandstone
Arenite (primarily composed of SiO2)
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement)
Mammoth Tooth
Mammuthus primigenius (Tooth fragment)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (primarily SiO₂ - Silicon Dioxide)
Petrified Wood
Silicified Wood (SiO2)
Limestone Pebble
Limestone (Calcium Carbonate, CaCO3)
Chert (Agatized)
Silicon Dioxide (SiO2)
Tumbled smoky quartz
Quartz (SiO₂), smoky variety
Vesicular volcanic rock, likely pumice or scoriaceous rhyolite
Vesicular rhyolite/dacite; predominantly silica-rich volcanic glass with feldspar and quartz
Sandstone (lithic wake or graywacke)
Clastic sedimentary rock (primarily quartz and lithic fragments)
Jasper with Iron Inclusions
Silicon Dioxide (SiO2) with Hematite/Goethite
River Stone (likely Quartzite or Sandstone)
Metamorphosed Quartz-rich Rock (SiO2)
Chert (specifically Flint or Common Opal)
Silicon Dioxide (SiO2)
Unakite (likely)
Epidote–pink feldspar–quartz rock; commonly termed unakite
Chert (Flint)
Microcrystalline Silicon Dioxide (SiO2)
Chert (Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (and/or Chalcedony)
Microcrystalline Silica (SiO2)