Sandstone (with manganese staining)
Clastic sedimentary rock (primarily SiO2)
Category
Browse organic gem material (botanical) specimens identified by the Rock Identifier community.
Sandstone (with manganese staining)
Clastic sedimentary rock (primarily SiO2)
Sandstone (with potential Arkose/Lithic characteristics)
Arenite (Sedimentary rock composed of sand-sized grains)
Pearl
Organic gemstone (Calcium carbonate / CaCO3 + Conchiolin)
Crushed Stone (Gravel/Aggregates)
Crushed rock aggregate (varied composition including Granite, Limestone, and Quartz)
Amber
Fossilized Tree Resin (Generic formula roughly C10H16O)
Quartz
Silicon dioxide (SiO2)
Quartz, Sandstone, and Siltstone specimens
Silicon Dioxide (SiO2) and Clastic Sedimentary Rocks
Concrete with Aggregate
Composite construction material; primary matrix is Calcium Silicate Hydrate (C-S-H)
Oak Wood (Wood Grain Pattern)
Quercus (genus)
Shale
Fissile mudrock (composed primarily of clay minerals and quartz)
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of cellulose)
Gray River Pebble (likely Limestone or Siltstone)
Sedimentary Rock (Calcium Carbonate or Siliciclastic)
Chert (with Epidote/Quartz veining)
Cryptocrystalline silica (SiO2) with Epidote/Quartz inclusions
Pyrite in Shale
Iron Sulfide (FeS2) in Sedimentary Matrix
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Chert (Jasper type)
Microcrystalline Quartz (SiO2)
Chert (Iron-stained)
Chert (SiO2)
Chert (Jasper type)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (Yellow/Tan variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Limestone with Chert or Siltstone bands
Sedimentary carbonate rock (CaCO3) often with siliceous impurities
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
Chert (Yellow Jasper variant)
Silicon Dioxide (SiO2)
Black Marble
Recrystallized Limestone (CaCO3)
Petrified Wood (Silicified Wood)
Silicified fossil wood (SiO2)
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Yellow variety / Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Pyrite
Iron Sulfide (FeS2)
Chert (Basanite / Flint)
Microcrystalline silica (SiO2)
Green Chert
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz or Cryptocrystalline Silica (SiO2)
Red Chert (Jasper)
Cryptocrystalline Quartz (SiO2) with iron oxide inclusions
Ironstone Concretion / Limonite Node
Goethite and Limonite (FeO(OH) nH2O)
Chert (Nodule)
Microcrystalline Quartz (SiO2)
Chert Pebble
Chert (Microcrystalline Quartz, SiO2)
Chert (often called Flint)
Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Silicon Dioxide (SiO2)
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Mosasaur Tooth Fossil
Mosasaurid vertebrate fossil (Hydroxyapatite)
Chert (Jasper/Flint variety)
Microcrystalline quartz (SiO2)