Diamond
Carbon (C)
Category
Browse antropogenic rock (man made) specimens identified by the Rock Identifier community.
Diamond
Carbon (C)
Petoskey Stone
Hexagonaria percarinata
Fossil Sea Urchin (Echinoid)
Echinoidea fossil (often replaced by silica or calcite)
Synthetic Convention Badge (Plastic/PVC)
Polyvinyl Chloride (PVC) / Polycarbonate
Obsidian
Volcanic Glass (70% or more SiO2)
Fossiliferous Limestone
Limestone (composed primarily of calcite with included fossils CaCO3)
Flint/Chert Nodule in Limestone
Sedimentary rock containing microcrystalline quartz (SiO2) within a calcium carbonate (CaCO3) matrix
Lapis Lazuli
Lapis Lazuli (Complex rock consisting primarily of Lazurite (Na,Ca)8(AlSiO4)6(S,SO4,Cl)1-2)
Diamond (or Diamond Simulant)
Carbon (C) or Cubic Zirconia (ZrO2)
Seashell Fragment
Calcium carbonate (CaCO3) - primarily Aragonite or Calcite
Diamond (Cut Gemstone)
Carbon (C)
Coquina
Bioclastic Limestone
Banded agate pendant (likely carnelian or brown-and-white chalcedony agate)
Agate, a banded variety of chalcedony; microcrystalline quartz, SiO₂, with iron-oxide coloration
Chert (specifically Yellow/Brown Chert or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide)
Diamond
Diamond (pure Carbon, C)
Obsidian
Obsidian (volcanic glass, amorphous silica rich rock)
Diamond Plate (Steel)
Alloyed Carbon Steel or Aluminum with 'Durbar' pattern
Sea Glass (Cobalt Blue)
Amorphous Silica (Glass with Cobalt additives)
Diamond
Carbon (C)
Engineered Quartz Stone
Agglomerated Quartz (SiO2 + Polymer Resin)
Fossilized echinoid (sea urchin), likely a flint/chalk-associated test
Echinoid fossil; likely a regular echinoid such as Echinocidaris or related taxon, composed mainly of recrystallized calcite (CaCO₃)
Diabase (Dolerite)
Diabase / Dolerite
Marble
Marble (metamorphosed limestone/dolostone). Predominantly composed of Calcite (CaCO3) for marble derived from limestone, or Dolomite (CaMg(CO3)2) for marble derived from dolostone.
Land Snail Shell
Gastropoda (Calcium Carbonate, CaCO3)
Diamond
Cubic carbon (C)
Sandstone
Arenite
Chert (variations include Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Pearl
Biogenic CaCO3 (Aragonite and Calcite)
Diamond
Diamond (pure Carbon, C)
Flint
SiO2 (Cryptocrystalline Quartz)
Pearl (Biogenic Mineraloid)
Calcium carbonate (CaCO3) primarily as Aragonite
Gypsum (Satin Spar / Alabaster variety)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
Chert
Chert (microcrystalline quartz)
US Penny
Cuprum (Copper: Cu) and Zincum (Zinc: Zn) Alloy
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Tumbled sodalite with white calcite veining
Sodalite, Na8(Al6Si6O24)Cl2, commonly intergrown with calcite, CaCO3
Fordite
Anthropogenic paint-rock
Granite Cobble/Pebble
Granite
Engineered Quartz (Quartzite look-alike)
Silicon Dioxide (SiO2) composite
Chert Arrowhead
Microcrystalline Quartz (SiO2)