Petrified Wood
Silicified Wood (primarily SiO2)
Category
Browse organic material (likely a fruit or berry) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified Wood (primarily SiO2)
Black tumbled stone, likely basalt or black jasper
Most consistent with fine-grained basalt (mainly plagioclase and pyroxene); exact identification requires testing
Tumbled blue chalcedony or pale aquamarine-like quartz
Chalcedony (microcrystalline SiO₂), possibly blue quartz; visual identification is uncertain
Chert (often called Flint or Jasper based on color)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Fossiliferous Limestone
Calcium Carbonate (CaCO3) - Limestone
Chert (Flint)
Chert (SiO2)
Black Chert (Flint)
Silicon Dioxide (SiO2)
Milky Quartz/Clear Quartz Cluster
Silicon Dioxide (SiO2)
Chert
Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony replacing $SiO_2$)
Petrified Wood
Silicified Wood (SiO2)
Red Jasper / Chert
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Chert / Jasper
Microcrystalline Quartz (SiO2)
Fossilized Shark Tooth
Scapanorhynchus (Sand Tiger Shark relative)
Red Jasper (possibly Petrified Wood)
Silicon Dioxide (SiO2) with Hematite inclusions
Chert (variations include Flint or Jasper)
Silicon Dioxide (SiO2)
Polished greenstone (likely serpentinite)
Serpentinite, chiefly antigorite/lizardite Mg₃Si₂O₅(OH)₄, possibly with magnetite
Weathered quartz-rich rock fragment
Likely quartz-bearing sandstone or granitic rock; exact identification is uncertain from the image
Ferruginous Sandstone (Ironstone)
Sedimentary rock with Limonite/Goethite cement
Likely weathered quartz-rich stone
Probably quartz-bearing sandstone or milky quartz; exact identification requires testing
Weathered limestone fragment
Calcitic limestone (mostly CaCO₃; possibly micritic limestone)
Sandstone (with biological crust)
Arenite (SiO2 based)
Quartz, Sandstone, and Siltstone specimens
Silicon Dioxide (SiO2) and Clastic Sedimentary Rocks
Sandstone (likely Fossiliferous)
Arenite / Fossiliferous Sandstone (SiO2 composition)
Chert (Nodule)
Microcrystalline Quartz (SiO2)
Flint
Chert (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Amber
Fossilized Tree Resin (C10H16O)
Fossilized Shark Tooth
Chondrichthyes (Class) fossilized tooth
Chert (Nodule)
Silicon Dioxide (SiO2)
Rounded river or beach pebble
Likely quartz-rich sandstone or quartzite; exact identification requires a close-grained view and hardness test
Gray River Pebble (likely Limestone or Siltstone)
Sedimentary Rock (Calcium Carbonate or Siliciclastic)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert / Jasper
Silicon Dioxide (SiO₂)
Quartz-bearing iron-stained breccia
Brecciated quartz/quartzite with iron oxides, chiefly SiO₂ with hematite/goethite and possible feldspar or host-rock fragments
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert / Jasper
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Flinty variety)
Microcrystalline Quartz (SiO2)
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxides