Lignite (Brown Coal)
Humic Lignite (Carbonaceous sedimentary rock)
Category
Browse sedimentary (man made conglomerate) specimens identified by the Rock Identifier community.
Lignite (Brown Coal)
Humic Lignite (Carbonaceous sedimentary rock)
Sandstone (Quartzose Sandstone)
Clastic sedimentary rock (primarily SiO2)
Favosites (Honeycomb Coral Fossil)
Favosites (Genus of extinct tabulate coral)
Sandstone (with biological crust)
Arenite (SiO2 based)
Chert (Gravel Bit)
Microcrystalline silica (SiO2)
Pyrite Geode (Sparkling Druzy)
Iron Sulfide (FeS2) in Sedimentary Nodule
Pyrite in Shale
Iron Disulfide (FeS2) in Sedimentary Shale
Quartz (likely Yellow/Orange variety, possibly Citrine or Chalcedony with iron staining)
Quartz (SiO₂)
Limonite and Goethite (Ironstone)
Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)
Milky Quartz
Silicon Dioxide (SiO2)
White Precious Opal
Hydrated Silica (SiO2·nH2O)
Pyrite
Iron Sulfide (FeS2)
Fluorite
Calcium Fluoride (CaF2)
Red Jasper
Silicon dioxide (SiO2) with iron oxide impurities
Ferruginous Quartz
Quartz (Silicon Dioxide, SiO2) with iron oxide inclusions
Satin Spar (Selenite)
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Chert (containing Quartz)
Microcrystalline Silica (SiO2)
Banded Calcite (often marketed as Caribbean Calcite)
Calcium Carbonate (CaCO3) + Aragonite
Ironstone Concretion (Limonite/Goethite)
Goethite-rich Concretion (FeO(OH))
Limestone
Calcium Carbonate (CaCO3)
Sandstone
Arenite (SiO2 based)
Sandstone (Quartz-rich Pebble)
Arenite (primarily SiO2)
Sandstone (Quartzite texture)
Arenite (SiO2 secondary)
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily SiO2 with Fe2O3 oxides)
Sandstone
Arenite (primarily SiO2)
Limestone
Calcium Carbonate (CaCO3)
Sandstone
Clastic sedimentary rock (primarily Quartz and Feldspar)
Jasper or Chert
Silicon Dioxide (SiO2)
Greywacke
Greywacke (Lithofeldspathic Sandstone)
Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)
Chert (microcrystalline quartz)
Quartz Geode
Silicon Dioxide (SiO2) in Geode form
Blue Chalcedony
Cryptocrystalline Quartz (SiO2)
Chalcedony (Common Opal variant)
Silicon dioxide (SiO2) with varying levels of hydration
Caribbean Calcite
Calcite (CaCO3) with Aragonite (CaCO3)
Iceland Spar (Optical Calcite)
Calcite (Calcium Carbonate, CaCO3)
Aragonite (Flos Ferri)
Calcium Carbonate (CaCO3)
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Graphite
Graphite (C)
Chert (Jasper variation)
Microcrystalline Quartz (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Chert (or Chalcedony)
Microcrystalline Quartz (SiO2)
Druzy Quartz
Silicon Dioxide (SiO2)