Sandstone
Arenite (SiO2 composed primarily of quartz)
Category
Browse organic (paper and cellulose) specimens identified by the Rock Identifier community.
Sandstone
Arenite (SiO2 composed primarily of quartz)
Petrified Wood and Mixed Rocks
Silicified Wood (SiO2)
Fossiliferous Limestone
Limestone (Calcium Carbonate - CaCO3)
Fossiliferous Limestone
Fossiliferous Calcite (CaCO3)
Shungite
Shungite (Non-crystalline carbon, C)
Fossiliferous Limestone with Brachiopod shell
Calcium carbonate (CaCO3)
Chalcedony (Common Opal variant)
Silicon dioxide (SiO2) with varying levels of hydration
Fossil Shark Tooth
Odontaspididae (likely Carcharias sp.)
Glauconitic Sandstone
Glauconitic Quartz Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)
Chert (Nodule)
Chert (Silicon Dioxide, SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert
Silicon dioxide (SiO2)
Chert (Yellow Jasper)
Cryptocrystalline Quartz (SiO2)
Chert (varieties: Flint, Jasper)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Chert
Microcrystalline Quartz (SiO2)
Chert (Yellow Jasper variant)
Silicon Dioxide (SiO2)
Black Jasper
Jasper (Silicon Dioxide, SiO2)
Chert (specifically Flint or Common Opal)
Silicon Dioxide (SiO2)
Glauconitic Sandstone
Glauconitic Sandstone (contains (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
Chert (Yellow Jasper/Flint)
Silicon dioxide (SiO2) - Cryptocrystalline Quartz
Chert (Jasper/Chalcedony)
Microcrystalline Quartz (SiO2)
Chert (Flint Nodules)
Silicon Dioxide (SiO2)
Amber
Succinite (Fossilized Tree Resin)
Chert (Flint)
Silicon Dioxide (SiO2)
Amber
Fossilized Tree Resin (Succinite for Baltic varieties)
Turquoise and Red Coral (with Grizzly Bear Claw)
Turquoise (CuAl6(PO4)4(OH)8·4H2O) and Precious Coral (Corallium rubrum)
Chert / Flint
Microcrystalline or cryptocrystalline Quartz (SiO2)
Sandstone (River Cobble)
Clastic sedimentary rock (primarily SiO2)
Red Coral
Corallium rubrum
Anthracite Coal
Carbon (with organic impurities)
Travertine
Travertine (a terrestrial form of Limestone, CaCO3)
Kidney Stone
Calcium Oxalate (CaC2O4), Uric Acid, or Struvite
Fossiliferous Limestone with Rugose Coral
Lithostrotionella (Limestone Matrix - CaCO3)
Fluorite
Fluorite (CaF2)
Glauconitic Sandstone
Glauconitic Sandstone (Greensand)
Fossiliferous Limestone
Calcite (CaCO3) matrix with biogenic fragments
Dendritic Agate
Silicon Dioxide (SiO2) with Manganese/Iron Oxide inclusions
Amber
Succinates (Organic Fossilized Resin)
Agate
Agate (a variety of Chalcedony, SiO2)
Marble
Marble (primarily Calcite, CaCO3 or Dolomite, CaMg(CO3)2)
Fluorite
Calcium Fluoride (CaF2)
Amber and Citrine Quartz
Succinite (Amber) and Silicon Dioxide (SiO2 / Citrine)