Chert (Gray Chalcedony)
Microcrystalline Quartz (SiO2)
Category
Browse organic (biological specimen) specimens identified by the Rock Identifier community.
Chert (Gray Chalcedony)
Microcrystalline Quartz (SiO2)
Fossiliferous Limestone
Calcium Carbonate - CaCO3
Moss Agate
Chalcedony (Silicon Dioxide - SiO2) with inclusions
Ambergris (Geological/Organic Specimen)
Ambra grisea (Produced by Physeter macrocephalus)
Fossiliferous Limestone
Biogenic Limestone with Brachiopod/Crinoid fragments
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
Chert Arrowhead (Projectile Point)
Microcrystalline Quartz (Chert/Flint)
Chert (Chalcedony/Jasper)
Microcrystalline Quartz (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Piddock bored rock (likely Mudstone or Shale)
Ichnofossil (Gastrochaenolites borings) in Fine-grained Sedimentary Rock
Petrified Wood
Silicified Wood (Permineralized organic matter, głównie $SiO_2$)
Petrified Wood
Silicified Wood (SiO2)
Banded Chert with Quartz Veining
Microcrystalline Quartz (SiO2)
Pyrite (Fool's Gold) in Matrix
Iron Disulfide (FeS2)
Chert (Nodule)
Chert (Silicon Dioxide, SiO2)
Chert (specifically River Stone / Jasper variety)
Microcrystalline Quartz (SiO2)
Hag Stone
Perforated Sandstone (composed of SiO2 and calcareous cement)
Tumbled chert or flint pebble
Microcrystalline quartz (SiO₂), likely chert; exact variety uncertain from the image
Moss Agate
Chalcedony (Silicon Dioxide) with inclusions - SiO2
Green Moss Agate
Silicon Dioxide with inclusions (SiO2)
Amethyst
Amethyst (Silicon Dioxide, SiO2 + Fe)
Coquina (Fossiliferous Limestone)
Coquina (Organic Clastic Limestone)
Purple Agate (Dyed Chalcedony)
SiO2 (Silicon Dioxide) with organic dyes
Chert (Jasper/Chalcedony)
Microcrystalline Silica (SiO2)
Fossiliferous Kalkstein (Marl/Sandstone)
Fossiliferous calcarenite/siltstone
Quartz Geode
Silicon Dioxide (SiO2) in sedimentary host rock
Chert (Flint)
Chert (Microcrystalline or cryptocrystalline Quartz, SiO2)
Moss Agate
Silicon Dioxide with inclusions (SiO2 + Mn/Fe/Chlorite)
Flower Jasper
Agatized Fossil Coral / Chalcedony (SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Chert (Flint) with Quartz Inclusions
Microcrystalline Quartz (SiO2)
Fossiliferous Limestone (Coquina)
Biogenic Limestone (Calcium Carbonate, CaCO3)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, SiO2)
Petrified Wood
Silicified wood (primarily quartz, SiO2)
Chert (Jasper variety)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Cryptocrystalline Quartz (SiO2)
Chert (Pebble)
Silicon Dioxide (SiO2)
Fossil Shark Tooth
Otodus sp. (likely Otodus obliquus) fossil
Fossil Shark Tooth
Elasmobranchii (Class) fossil - possibly Odontaspididae family
Chert (Jasper variation)
Silicon Dioxide (SiO2)
Jasper with Quartz Vein
Silicon Dioxide (SiO2) with impurities
Petrified Wood (Silicified Wood)
Silicified Wood / Silicon Dioxide (SiO2)