Agatized Chert / Chalcedony
Silicon Dioxide (SiO2)
sedimentary
Category
Organic (Biological Specimen)
Browse organic (biological specimen) specimens identified by the Rock Identifier community.
Septarian Nodule
Septarian Concretion (CaCO3 with Siderite/Calcite/Aragonite)
sedimentary
Glauconitic Sandstone (Greensand pebble)
Glauconitic Quartz Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
fossil
Possible fossilized ammonite or concretion
Indeterminate fossil specimen; possibly an ammonoid mold/cast in iron-rich sedimentary rock
fossil
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Basalt with Desert Varnish
Mafic Volcanic Rock (Fe/Mg rich silica)
igneous
Chert (Jasper-bearing)
Silicon dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Chert (and Jasper variety)
Microcrystalline Quartz (SiO2)
sedimentary
Blue Agate (Tumbled and Dyed)
Silicon Dioxide (SiO2) with likely organic dyes
mineral
Shale with Plant Fossils / Carbonaceous Shale
Laminated Mudrock (Siliciclastic)
sedimentary
Chert (Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (specifically Yellow Jasper variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified wood (primarily Silicon Dioxide - SiO2)
mineral (silicate-replaced organic material)
Chert (Iron-stained River Cobble)
Microcrystalline Quartz (SiO2)
sedimentary
Fossilized Shark Tooth (Fragment) in Matrix
Elasmobranchii (subclass)
fossil
Flint (Chert)
Silicon Dioxide (SiO2)
sedimentary
Moss Agate
Silicon Dioxide (SiO2) with inclusions of hornblende, chlorite, or manganese/iron oxides
mineral
Limestone
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Mookaite Jasper
Silicified Radiolarite (SiO2)
sedimentary
Tiger Iron
Tiger Iron (Hematite, Red Jasper, and Chert/Tiger's Eye composite)
metamorphic
Amber with dark mineral/organic inclusions
Fossilized plant resin (amber; chiefly polymerized diterpenoid resin)
gemstone
Green Chert (Jasper)
Microcrystalline Quartz (SiO2) with chlorite/epidote inclusions
sedimentary
Ironstone / limonite-rich concretion
Hydrated iron oxides, chiefly limonite/goethite (FeO(OH)·nH₂O), possibly with hematite
mineral
Jasper with Quartz Vein
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement)
fossil
Hematite (Iron Ore)
Iron(III) oxide (Fe2O3)
mineral
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Chert (Green variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Calcite
Calcium Carbonate (CaCO3)
mineral
Flint
Chert (Cryptocrystalline Quartz, SiO2)
sedimentary
Chert (Grey-Green Var.)
Silicon Dioxide (SiO2)
sedimentary
Chert (Jasper/Common Opal transition)
Microcrystalline Quartz (SiO2) with iron oxide inclusions
sedimentary
Graphite-bearing schist (probable)
Graphite–quartz–mica schist; chiefly graphite (C), quartz (SiO₂), and mica
metamorphic
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Fossil Shark Tooth
Carcharhinidae or Lamniformes sp. (possibly Carcharodon or Otodus genus)
fossil
Brachiopod Fossil
Phylum Brachiopoda (likely Order Rhynchonellida or Spiriferida)
sedimentary
Chert (Chert Nodule with Cortex)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Iron-stained)
Chert (primarily Microcrystalline Quartz, SiO2)
sedimentary
Carved Mottled Greenish-Yellow Crystal/Glass Object
Unknown; possibly a form of quartz (chalcedony/jadeite/nephrite) or glass/resin.
Man-made Object/Uncertain Mineral
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood / Chalcedony (SiO2)
sedimentary