Ironstone Concretion (Limonite/Goethite)
Iron oxide concretion (contains FeO(OH)·nH2O)
Category
Browse organic (paper and cellulose) specimens identified by the Rock Identifier community.
Ironstone Concretion (Limonite/Goethite)
Iron oxide concretion (contains FeO(OH)·nH2O)
Amber
Succinate (Fossilized Tree Resin)
Agate (Moss or Dendritic Agate)
Chalcedony (Silicon Dioxide, SiO2)
Natural White Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin - CaCO3
Coal (likely Bituminous or Lignite)
Organic Sedimentary Rock (Carbonaceous)
Bituminous Coal (with Anthracite or Vitrinite inclusion)
Organic-rich Sedimentary Rock (Carboniferous classification)
Fossiliferous Limestone with Rugose Coral
Calcium Carbonate (CaCO3) featuring Rugosa (extinct order of solitary and colony corals)
Lemon (Mock specimen mimicking Citrine/Sulfur)
Citrus x limon
Chert (and/or River Pebble)
Microcrystalline quartz (SiO2)
Chert (specifically Flint or Dark Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper/River Stone)
Silicon dioxide (SiO2) - Microcrystalline quartz
Chert (Tan/Yellow variety)
Microcrystalline Quartz (SiO2)
Chert (White Chert / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
Petrified Wood
Silicified Wood (primarily SiO2)
Chert (and Flint)
Silicon dioxide (SiO2) - Microcrystalline quartz
Chert (Flint variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert Nodule (Fossiliferous Chert)
Microcrystalline Quartz (SiO2)
Chert (Jasper/Jasperoid)
Chert (chemically precipitated microcrystalline Quartz, SiO2)
Chert / Flint
Chert (Cryptocrystalline Silica, SiO2)
Chert (White Chert)
Microcrystalline Quartz (SiO2)
Chert (variously Flint)
Chert (Microcrystalline or cryptocrystalline Quartz, SiO₂)
Chert (often called Flint)
Chert (Microcrystalline Quartz, SiO2)
Chert (Jasper/Chalcedony)
Microcrystalline Quartz (SiO2)
Yellow Jasper (Chert)
Silicon Dioxide (SiO2) with iron inclusions
Chert (and Flint variant)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (Tan or Buffer variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Chert (Jasper)
Silicon dioxide (SiO2)
Chert (Smooth River Pebble)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Petrified Wood (Calamites Fossil)
Calamites sp. (Silicified/Permineralized Plant Fossil)
Geode (unopened)
Chert / Chalcedony Geode (SiO2)
Ammonite Fossil
Ammonoidea (Calcium carbonate - CaCO3)
Amber
Amber (C10H16O)
Greenstone / Chert
Cryptocrystalline Quartz (SiO2) or Altered Basalt
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Red Chert (Jasper)
Microcrystalline Quartz (SiO2)
Jasper
Silicon dioxide (SiO2)
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (specifically Gray Chert)
Chert (SiO2)