Red Sandstone
Sandstone (Quartz Arenite / Arkose with Hematite cement)
Category
Browse organic material specimens identified by the Rock Identifier community.
Red Sandstone
Sandstone (Quartz Arenite / Arkose with Hematite cement)
Petrified Wood
Silicified Wood (primarily SiO2)
Jasper
Silicon dioxide (SiO2)
Black Jasper (Etched)
Silicon Dioxide (SiO2) with impurities
Chalcedony
Cryptocrystalline Quartz (SiO2)
Jasper (Green/Yellow Moss Jasper)
Silicon Dioxide (SiO2)
Fossil Coral
Scleractinia or Anthozoa (Fossilized)
Ironstone Concretion
Ironstone (primarily Siderite or Limonite)
Red Jasper with Quartz
Microcrystalline Quartz (SiO2)
Yellow Chert (Chalcedony)
Microcrystalline Quartz (SiO2)
Amber-like beach pebble
Amber (fossilized tree resin), likely heavily weathered or resinous organic material; exact identification is uncertain from the image
Chert (often called Flint when found in chalk)
Microcrystalline Quartz (SiO2)
Fossilized Bone
Permineralized Vertebrate Bone
Jasper
Silicon Dioxide (Microcrystalline Quartz), SiO2
Petrified Wood
Silicified Wood (primarily SiO2)
Microcrystalline Quartz (Chert/Agate)
Silicon Dioxide (SiO2)
Fossilized Shark Tooth
Chondrichthyes (Class) - likely Carcharodon or Otodus genus
Jasper
Silicon Dioxide (Microcrystalline Quartz, $SiO_2$)
Chert with Iron Inclusions
Microcrystalline Quartz (SiO2) with Hematite/Limonite
Starfish Fossil
Asteroidea fossil
Fossil Shark Tooth
Chondrichthyes tooth fossil
Jasper
Microcrystalline Quartz (SiO2)
Green Jasper
Jasper (Silicates, SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Chert (Jasper-bearing)
Microcrystalline silica (SiO2) with iron oxide inclusions
Chert (Fossiliferous)
Silicon dioxide (SiO2)
Chert (often found as Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Yellow Jasper/Flint)
Microcrystalline Quartz (SiO2)
Petrified Wood (Black / Carbonized)
Silicon Dioxide (Quartz/Chalcedony replacing Organic Matter)
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (SiO2)
Beach sandstone or cemented beachrock fragment
Lithified carbonate- or silica-rich sand; commonly calcarenite or quartz sandstone
Sandstone
Sandstone (Quartz-rich Arenite / SiO2)
Quartz (Chert/Chalcedony variety)
Silicon Dioxide (SiO2)
Chert (or Chalcedony)
Microcrystalline Quartz (SiO2)
Jasper
Silicon dioxide (SiO2)
Jasper
Silicon Dioxide (SiO2) with impurities
Fancy Jasper
Jasper (Cryptocrystalline Quartz, SiO2)
Jasper
Jasper (Cryptocrystalline variety of Quartz, SiO2)
Agatized Fossil or Chalcedony Nodule
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Petrified Wood
Silicified Wood (SiO2 permineralization)