Diamond (Cut Gemstone)
Carbon (C)
Category
Browse anthropogenic (man made material) specimens identified by the Rock Identifier community.
Diamond (Cut Gemstone)
Carbon (C)
Diamond (or Diamond Simulant)
C (Carbon) or synthetic equivalent
Diamond
C (Carbon)
Diamond (or Diamond Simulant)
Carbon (C) if diamond, various if simulant
Tumbled honey-colored chalcedony or quartzite
Microcrystalline quartz, SiO₂; exact identification requires testing
Brown Jasper / River Siltstone
Silicon Dioxide (SiO2) with iron oxide impurities
Diamond
Diamond (pure carbon, C)
Ferruginous Sandstone (Ironstone Conglomerate fragments)
Ferruginous clastic sedimentary rock (SiO2 cemented by Fe2O3)
Zebra Jasper
Tetragonal Silicon Dioxide (Quartz) with impurities
Schist
Mica schist, likely muscovite–biotite schist with quartz and feldspar
Greenstone / Serpentinite Pebble
Serpentinite (Hydrated Magnesium Silicate, Mg3Si2O5(OH)4)
Limestone
Calcium Carbonate (CaCO3)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Sandstone Pebble
Sandstone (primarily Quartz, SiO2)
Sandstone
Arenite (SiO2 primarily)
Sandstone
Arenite (SiO2 primarily)
Tree Agate
Silicon dioxide (SiO2)
Amber
Succiniferous organic material (Succinite)
Faceted blue gemstone, likely blue topaz or synthetic spinel
Topaz (Al₂SiO₄(F,OH)₂) or synthetic spinel (MgAl₂O₄); image insufficient for certainty
Vesicular basalt (likely weathered scoria)
Basaltic volcanic rock; chiefly plagioclase, clinopyroxene, and olivine with vesicles
Tumbled green gemstone, likely dyed howlite or serpentine
Most consistent with dyed howlite (Ca2B5SiO9(OH)5); exact identification requires testing
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Jasper (Multi-color Chert)
Silicon Dioxide (SiO2) with impurities
Sandstone (Quartzose Sandstone)
Clastic sedimentary rock (primarily SiO2)
Petrified Wood
Petrified Wood (Silicified Wood)
N/A - Image is non-geological
Acrylonitrile Butadiene Styrene (ABS) or Polypropylene (PP)
Likely petrified wood or silicified fossil fragment
Silicified wood; predominantly microcrystalline quartz (SiO₂)
Quartz Sand
Silicon Dioxide (SiO2)
Crushed Limestone
Calcium Carbonate (CaCO3)
Quartz-rich pegmatitic rock (likely quartz–feldspar–mica specimen)
Granitic pegmatite; mainly quartz (SiO₂), feldspar, and dark mica/amphibole
Gray chalcedony (microcrystalline quartz)
Chalcedony, SiO₂; likely common gray/blue-gray variety
Chert Pebble
Microcrystalline Quartz (SiO2)
Jasper
Silicon Dioxide (SiO2) with impurities
Red Sandstone
Arenite (Iron-rich)
Serpentinite (or Green Quartz Pebble)
Mg3Si2O5(OH)4 (Serpentine group) / SiO2 (Quartz mix)
Sandstone (Quartzose Sandstone)
Clastic Sedimentary Rock (primarily SiO2)
Granite
Granite
Fossiliferous Sandstone / Fossil Fragment
Fossiliferous Sedimentary Matrix with Indeterminate Fossil Material
Flint
SiO2 (Microcrystalline Quartz / Chert)
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)