Sandstone
Arenicola (comprising mostly Quartz, SiO2)
sedimentary
Category
Organic (Sedimentary Context)
Browse organic (sedimentary context) specimens identified by the Rock Identifier community.
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Chert (Gray Chalcedony)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (White-Tan variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Tufa
Calcareous Tufa (Calcium Carbonate, CaCO3)
sedimentary
Fossilized Shark Tooth
Fossilized elasmobranch tooth (Apatite/Calcium Phosphate)
sedimentary
Chert (Flint)
Cryptocrystalline quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO₂)
sedimentary
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula: SiO2)
sedimentary
Polished/tumbled calcite
Calcite (calcium carbonate, CaCO₃)
mineral
Amber (Raw Copal)
Fossilized Plant Resin (Gummite/Succinite)
mineral
Green Moss Agate
Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Pink Opal
Hydrated Amorphous Silica (SiO2·nH2O)
mineraloid
Sandstone (Red / Iron-stained)
Sandstone (composed predominantly of SiO2 with Fe2O3 cement)
sedimentary
Amber
Succinate (Fossilized Tree Resin)
mineraloid
Petrified Wood
Silicified Wood (SiO2)
fossil
Petrified Wood
Silicified Wood (primarily SiO2)
metamorphic
Lepidodendron Fossil (Scale Tree)
Lepidodendron
fossil
Petrified Wood
Silicified wood (primarily SiO2 - Silicon Dioxide/Quartz)
metamorphic
Petrified Wood
Silicified Wood (SiO2)
fossil
Petrified Wood
Silicified Wood (SiO2)
fossil
Petrified Wood
Silicified wood (primarily quartz, SiO2)
sedimentary
Sandstone Pebble (River Rock)
Sandstone (Quartz-rich sedimentary rock with iron oxide staining)
sedimentary
Limestone ( weathered ) / Chert Nodular Rock
Sedimentary rock (primarily Calcium Carbonate, CaCO3, with Microcrystalline Quartz, SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Limestone (Weathered Pebble)
Calcium Carbonate (CaCO3) / Limestone
sedimentary
Fossiliferous Rock (likely Dinosaur Fossil in Matrix)
Permineralized Vertebrate Fossil (Calcium Carbonate/Silica replaced bone material)
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Chert (and/or Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Jasper/Flint variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (varietal: Jasper or Flint)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Septarian Nodule (Dragon Stone)
Septarian concretion (composition: CaCO3 - Calcite, Aragonite, and Siderite/Limestone)
sedimentary
Fossiliferous Limestone (Coquina)
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Chert (variant Flint)
Silicon Dioxide (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Chert Pebble (Jasper variety)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Red Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary