Sandstone Geode (Ironstone Concretion)
Arenite with Limonite/Hematite matrix (SiO2 with Fe-oxides)
sedimentary
Category
Anthropogenic Material (Man Made Sedimentary Mimic)
Browse anthropogenic material (man made sedimentary mimic) specimens identified by the Rock Identifier community.
Diamond
Native Carbon (C)
mineral
Bauxite
Bauxite (Al(OH)3, AlO(OH))
sedimentary
Banded Calcite (often commercially sold as 'Mexican Onyx' or 'Honey Onyx')
Calcite (Calcium Carbonate, CaCO3)
sedimentary
Rough Diamond
Pure Carbon (C)
mineral
Chert (specifically Jasper or Flint variety)
Cryptocrystalline Quartz (SiO2)
sedimentary
Diamond
Carbon (C)
mineral
Cobalt Blue Slag Glass
Amorphous Silicon Dioxide (anthropogenic) with Cobalt additives
mineraloid
Crushed Limestone
Calcium Carbonate (CaCO3)
Sedimentary
US Penny
Cuprum (Copper: Cu) and Zincum (Zinc: Zn) Alloy
Man-made object (metal alloy)
Jasper (Banded Jasper)
Silicon Dioxide (SiO2) with impurities
sedimentary
Diamond (as set in a gold ring)
Carbon (C)
mineral
Carnelian
Chalcedony (cryptocrystalline quartz), SiO2
Mineral
Sandstone (Picture Sandstone)
Arenite (primarily SiO2 with iron oxide impurities)
sedimentary
Chert (Beach Pebble)
Microcrystalline Quartz (SiO2)
sedimentary
Quartzite Arrowhead (Archaeological Lithic)
Recrystallized Quartz (SiO2)
metamorphic
Asphalt
Asphalt concrete (engineered material, not a naturally occurring rock/mineral in this form)
Sedimentary
Coquina
Bioclastic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Onyx (Black) and Mother of Pearl Inlay
Silicon Dioxide (SiO2) for Onyx; Aragonite (CaCO3) for Mother of Pearl
mineral
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flinty variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (specifically Zebra Chert/Flint)
Silicon Dioxide (SiO2)
sedimentary
Asphalt (Bituminous Concrete)
Composite material (bitumen binder with mineral aggregate)
man-made rock (technosol)
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Opalite
Man-made synthetic glass with opalescent effects (SiO2 + metal oxides)
mineraloid
Slag Glass (Cullet)
Amorphous Silica (man-made), primarily SiO2 with trace metal oxides
Mineraloid / Synthetic Glass
Boxwork Quartz / Septarian Jasper
Boxwork (SiO2 with iron oxide inclusions)
metamorphic
Diamond (in Jewelry)
Carbon (C)
mineral
Red Dyed Howlite
Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)
mineral
Chert (Nodular or Massive Variety)
Cryptocrystalline Quartz (SiO2)
sedimentary
Pyrite
Iron Sulfide (FeS2)
mineral
Diamond (Cut jewelry specimen)
Diamond (pure Carbon, C)
mineral
Slag (Industrial Glass/Metal)
Ferrous slag or Glassy silicate byproduct
Antropogenic rock (Man-made)
Chert (Grey-Green Flint)
Microcrystalline silicon dioxide (SiO2)
sedimentary
Diamond
Diamond (pure Carbon, C)
mineral
Aragonite Star Cluster
Aragonite (Calcium Carbonate, CaCO3)
mineral
Chert (Iron-stained)
Chert (Microcrystalline and Cryptocrystalline Quartz, SiO2)
sedimentary
Diamond
Diamond (pure Carbon, C)
mineral
Coquina
Coquina (Bioclastic Limestone)
sedimentary
Tektite (Indochinite)
Tektite (Amorphous Silica Glass)
igneous
Chert (Arrowhead variety)
Chert (SiO2)
sedimentary
Man-made Blank Ammunition (Brass)
CuZn (Cartridge Brass - roughly 70% Copper, 30% Zinc)
Anticrystalline / Synthetic Alloy