Chert (Jasper / Flint variant)
Microcrystalline Quartz (SiO2)
sedimentary
Category
Sedimentary (Biogenic Sediment Or Biological Remain)
Browse sedimentary (biogenic sediment or biological remain) specimens identified by the Rock Identifier community.
Learn about Sedimentary (Biogenic Sediment Or Biological Remain) in the encyclopedia
View all →
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Cockle Shell (Fossil or Recent)
Class Bivalvia, Family Cardiidae (e.g., Cerastoderma edule for common cockle)
Sedimentary (Biogenic, a type of fossil)
Weathered limestone pebble
Limestone, primarily calcite (CaCO₃)
sedimentary
Limestone with Lichen
Calcium Carbonate (CaCO3) with Endolithic/Epilithic Lichen
sedimentary
Chert / Flint
Cryptocrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2 permineralization)
sedimentary
Petrified Wood
Silicified wood (Quartz/Chalcedony - SiO2)
sedimentary
Fossiliferous limestone, possibly containing a brachiopod or bivalve fossil
Calcite-rich limestone (CaCO₃), with an apparent shell impression or shell fragment
fossil
Green Jasper Pebble
Microcrystalline Quartz (SiO2) with impurities
sedimentary
Ironstone Concretion
Ironstone (Limonite/Goethite/Hematite mixture)
sedimentary
Siltstone Concretion
Carbonate-cemented Siltstone Concretion
sedimentary
Ironstone Concretions (Ironstone)
Ferruginous Sandstone or Siltstone (Fe2O3)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with iron inclusions
mineral
Jasper
Silicon dioxide (SiO2) with impurities
sedimentary
Honeycomb Coral Fossil
Favosites (extinct genus of tabulate coral)
sedimentary
Shark Tooth Fossil
Otodus obliquus (or similar prehistoric lamniform shark tooth)
fossil
Fossil Shark Tooth (embedded in matrix)
Lamniformes (likely Cretalamna or Squalicorax) within phosphatic/calcareous matrix
sedimentary
Fossiliferous Chert or Limestone
Sedimentary rock containing fossilized marine invertebrates (likely crinoid stems or bryozoans)
sedimentary
Yellow Jasper
Chalcedony (SiO2 with iron oxide inclusions)
mineral
Ironstone Concretion (Nutstone)
Ironstone (with High Limonite/Hematite Content)
sedimentary
Druzy Quartz Geode (Partially Open)
Silicon Dioxide (SiO2) within Sedimentary Host Rock
sedimentary
Amber
Succinate (Fossilized Tree Resin)
mineraloid
Chert (variations include Flint or Jasper)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Honeycomb Calcite
Calcite (Calcium Carbonate, CaCO3)
sedimentary
Tufa (Calcareous Tufa)
Calcareous Tufa (Precipitated CaCO3)
sedimentary
Weathered gray sandstone or siltstone
Clastic siliciclastic rock, primarily quartz and feldspar grains cemented by silica or carbonate
sedimentary
Amber
Succinite (approximate formula C10H16O)
mineraloid
Chert Nodule (Fossiliferous Chert)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone (Water-worn Pebble)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Tufa
Calcareous Tufa (CaCO3)
sedimentary
Fossilized Rugose Coral
Order Rugosa (Calcium Carbonate - CaCO3)
sedimentary
Dinosaur Bone (Fossilized)
Permineralized Bone (CaCO3 or SiO2 after Hydroxylapatite)
sedimentary
Fossilized Coral
Anthozoa (Fossilized)
Sedimentary / Fossil
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Chert
Cryptocrystalline Quartz (SiO2)
sedimentary
Sandstone Concretion
Moqui Marble / Ironstone Concretion (Iron oxide-cemented sandstone)
sedimentary
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of organic matter)
sedimentary
Ironstone Concretion
Siderite or Hematite Concretion (FeCO3 or Fe2O3)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily Quartz / Chalcedony: SiO2)
sedimentary
Smooth gray river pebble
Likely fine-grained sandstone or siltstone; exact identification requires a fresh surface and tests
sedimentary