Chert (Flint)
Microcrystalline Quartz (SiO2)
Category
Browse organic structure (not a rock) specimens identified by the Rock Identifier community.
Chert (Flint)
Microcrystalline Quartz (SiO2)
Quartz pebble or seed/crumb
SiO2 (if quartz)
Coral Fossil (Petrified Coral)
Scleractinia (Order) - Calcified Fossil Skeleton (CaCO3)
Limestone with Stylolites
Calcareous sedimentary rock (CaCO3)
Petrified Wood
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
Chert / Flint
Chert (Microcrystalline Quartz, SiO2)
Limestone pebble
Sedimentary rock, primarily calcium carbonate (CaCO3)
Fossiliferous Limestone
Biogenic Sedimentary Rock / CaCO3 with fossil fragments
Chert (variations include Flint or Jasper)
Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Fossilized Bone
Permineralized Bone (Vertebrate Fossil)
Jasper (specifically Polychrome or Desert Jasper)
Silicon Dioxide (SiO2) with iron oxide and other mineral impurities
Fossil Shark Tooth
Selachii (fossilized dentition)
Petrified Wood
Silicified Wood (SiO2)
Chert (Flint/Jasper variety)
Silicon Dioxide (SiO2)
Limestone (Fossiliferous)
Calcium Carbonate (CaCO3)
Chert (Flint)
Chert (SiO2)
Petrified Wood
Silicified Wood (Silicon Dioxide - SiO2)
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Fossilized bone fragment (probable mammalian tooth or bone)
Mineralized bone, commonly hydroxyapatite [Ca5(PO4)3(OH)] replaced or impregnated by silica/calcite
Concretion
Septarian or Siderite Concretion
Shale
Shale (Sedimentary rock composed of mud/clay minerals)
Green Chert
Microcrystalline Quartz (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Shungite
Non-crystalline carbon (similar to anthracite coal or meta-anthracite)
Chert (Chalcedony/Flint)
Silicon Dioxide (SiO2)
Bituminous Coal
Coal (Organically derived sedimentary rock)
Bivalve Fossil in Sedimentary Matrix
Fossiliferous Mudstone (Class: Bivalvia)
Chert (White-Tan variety)
Silicon dioxide (SiO2) / Microcrystalline Quartz
Chert (Yellow Jasper/Flint)
Microcrystalline Quartz (SiO2)
Chert / Flint
Chert (Silicon Dioxide, SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert (Flint Nodules)
Silicon Dioxide (SiO2)
Chert (Flint Pebbles)
Microcrystalline Quartz (SiO2)
Amber
Fossilized Tree Resin
Amber
Succinite (C10H16O)
Coquina
Biogenic Limestone (Calcium Carbonate - CaCO3)
Quartz Geode
Silicon Dioxide (SiO2)
Chert (specifically Flint or Jasper variant)
Microcrystalline Quartz (SiO2)
Chalcedony
Cryptocrystalline Quartz (SiO2)