Coal (specifically Bituminous or Anthracite)
Organic sedimentary rock; primarily Carbon (C) with varying H, S, O, N
Category
Browse sedimentary (chemical) specimens identified by the Rock Identifier community.
Coal (specifically Bituminous or Anthracite)
Organic sedimentary rock; primarily Carbon (C) with varying H, S, O, N
Garnet
Almandine (Fe3Al2(SiO4)3)
Chert (variations include Flint)
Silicon Dioxide (SiO2)
Limestone
Calcium Carbonate (CaCO3)
Chert (or Cryptocrystalline Quartz)
Silicon Dioxide (SiO2)
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Yellow Calcite
Calcium Carbonate (CaCO3)
Weathered limestone fragment
Limestone, predominantly calcite (CaCO₃), possibly porous bioclastic limestone
Crushed Limestone
Calcium Carbonate (CaCO3)
Rock salt (Halite)
Halite (Sodium Chloride, NaCl)
Limestone
Calcium Carbonate (CaCO3 / Calcite)
Limestone (Weathered)
Calcium Carbonate (CaCO3)
Sandstone with Liesegang Rings
Arenite with secondary Iron oxide (Limonite/Goethite) precipitation
Coal (likely Anthracite)
Anthracite coal
Chert (Jasper)
Sedimentary Cryptocrystalline Quartz (SiO2)
Limestone Pebble
Sedimentary Calcium Carbonate (CaCO3)
Limestone
Calcareous sedimentary rock (CaCO3)
Jasper-Quartz Conglomerate / Chert
Siliceous Sedimentary Rock (SiO2)
Chert (variably Oolitic or Fossiliferous)
Sedimentary Cryptocrystalline Quartz (SiO2)
Chert (Jasper-rich)
Silicon Dioxide (SiO2)
Chert (Pink/Tan variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Nodule)
Microcrystalline quartz (SiO2)
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Ironstone / Weathered Hematite
Iron oxide-rich sedimentary rock with Goethite/Hematite
Chert (specifically brown Chert or Jasper)
Microcrystalline Quartz (SiO2)
Chert (River Pebble)
Microcrystalline Silica (SiO2)
Chert (often called Flint)
Chert (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Chert (White Chert)
Silicon Dioxide (SiO2)
Iron-rich sulfide-bearing rock, likely pyrite-rich shale or limonite-goethite specimen
Likely pyrite (FeS₂) with oxidation products goethite/limonite (FeO(OH)·nH₂O), possibly in shale or quartz matrix
Blue Calcite Sphere
Calcium Carbonate (CaCO3)
Coarse Sand or Fine Gravel
Detrital Sedimentary Fragments (mostly SiO2)
Light-colored quartz-rich pebble
Likely quartz (silicon dioxide, SiO₂), possibly a weathered quartzite fragment
Weathered iron-rich rock, possibly laterite or limonite-bearing sandstone
Laterite/ironstone; mainly hydrated iron oxides such as limonite/goethite (FeO(OH)·nH₂O), with possible quartz and clay minerals
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Chert (Jasper/Agate)
Cryptocrystalline Quartz (SiO2)
Blue Calcite
Calcium Carbonate (CaCO3)
Chert (Jaspery variety)
Microcrystalline Quartz (SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert
Chert (Microcrystalline Quartz, SiO2)
Chert (Black Chert or Flint)
Silicon Dioxide (SiO2)