Sandstone
Arenite (mostly SiO2)
Category
Browse anthropogenic (man made) specimens identified by the Rock Identifier community.
Sandstone
Arenite (mostly SiO2)
Tumbled chert or jasper pebble
Microcrystalline quartz (SiO₂), likely chert/jasper
Sandstone
Arenite (with iron oxide cement)
Calligraphy Stone
Mariam Jasper (Fossiliferous Limestone composed of Hematite and Shell remains)
Synthetic Convention Badge (Plastic/PVC)
Polyvinyl Chloride (PVC) / Polycarbonate
Diamond
Diamond (pure Carbon, C)
Gypsum (Satin Spar / Alabaster variety)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
Diamond
Carbon (C)
Limestone Pebble
Sedimentary Calcium Carbonate (CaCO3)
Quartzite
Metamorphic Quartzite (SiO2)
Quartzite
Metamorphic Quartz Rock (SiO2)
Exposed aggregate concrete (stone-chip surface)
Portland-cement concrete containing natural aggregate; not a natural rock
Sandstone
Arenite (SiO2 primarily)
Chalk
Carbonate rock (mainly CaCO3)
Pearl
Aragonite / Calcium Carbonate (CaCO3)
Diamond (in Jewelry)
Carbon (C)
Weathered concrete or cementitious slab (not natural rock)
Artificial calcium-silicate cement composite; likely Portland cement concrete
Sandstone
Arenite (SiO2 composition dominant)
Tumbled quartz-rich pebble
Microcrystalline quartz (SiO₂), possibly milky quartz or quartzite
Blue-green chrysocolla rough specimen
Chrysocolla, hydrated copper aluminosilicate; commonly associated with malachite, quartz, and limonite
Quartzite
Metamorphic Quartzite (SiO2)
Polished/tumbled brown-and-white mineral fragment
Indeterminate; possibly quartz-rich jasper, brecciated jasper, or an iron-stained quartz mineral
Diamond
Native Carbon (C)
Diamond
Carbon (C)
Chert (Flint)
Silicon Dioxide (SiO2)
Sandstone
Arenite (composed primarily of SiO2)
Chalk
Micrite (primarily Calcium Carbonate or CaCO3)
Orange glassy slag (industrial by-product)
Iron-rich silicate glass; composition varies, commonly Fe–Ca–Al silicate
Pearl
Organic gemstone (Calcium carbonate - CaCO3)
Chert (variations include Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Sandstone
Arenite (SiO2, often with CaCO3 or Fe2O3 cement)
Sandstone (Quartzose)
Sandstone (SiO2 dominated)
Diamond
Carbon (C)
Diamond
Carbon (C)
Quartzite
Metamorphic Quartzite (SiO2)
Coal (Bituminous Coal)
Caustobiolith / Sedimentary Rock
Diamond
Diamond (pure carbon C)
Quartzite
Metamorphic Quartz Rock (SiO2)
Red Quartzite
Quartzite (Metamorphosed Quartz Arenite)
Quartzite
Metamorphic Quartzite (SiO2)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Sandstone
Clastic Sedimentary Rock