Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Category
Organic (Non Geological)
Browse organic (non geological) specimens identified by the Rock Identifier community.
Obsidian
Volcanic Glass (70% or more SiO2)
igneous
Black Obsidian
Volcanic Glass (Silicon Dioxide with impurities)
igneous
Man-made Blank Ammunition (Brass)
CuZn (Cartridge Brass - roughly 70% Copper, 30% Zinc)
Anticrystalline / Synthetic Alloy
Fossil bone or tooth fragment
Mineralized fossil vertebrate bone/tooth; exact taxon cannot be determined from the photograph
fossil
Petrified Wood
Silicified wood (SiO2)
fossil
Pink Coral
Corallium rubrum (or related species, composed of calcium carbonate)
gemstone
Fossiliferous Kalkstein (Marl/Sandstone)
Fossiliferous calcarenite/siltstone
sedimentary
Tumbled pale green aventurine or common green quartzite
Quartz, SiO₂, likely with fuchsite or chlorite inclusions
mineral
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Obsidian
Volcanic Glass (Amorphous Silica)
igneous
Obsidian
Obsidian (Volcanic Glass, primarily SiO2)
igneous
Quartzite
Quartzite (primarily SiO2)
metamorphic
Laterite
Laterite (Iron and Aluminum-rich residual soil/rock)
sedimentary
Weathered sandstone fragment
Sandstone, chiefly quartz (SiO₂) with feldspar and iron-oxide cement
sedimentary
Blue Goldstone
Aventurine Glass
Man-made mineral simulant (Glass)
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Libyan Desert Glass
Libyan Desert Glass (SiO2 with trace elements)
mineral (impactite)
Quartzite Pebble
Quartzite (primarily SiO2)
metamorphic
Siderite Concretion in Shale
Iron carbonate (FeCO3) in Mudstone/Shale matrix
sedimentary
Polished moss agate (likely)
Chalcedony, microcrystalline quartz (SiO₂), with dark mineral inclusions
mineral
Quartzite
Quartzite (SiO2)
metamorphic
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Fossilized Bivalve
Phylum Mollusca
fossil
Pearl necklace with small blue-green gemstone accents
Pearls: nacre, chiefly aragonite (CaCO₃) and conchiolin; accents appear to be turquoise or similar opaque blue-green stone
gemstone
Petrified Wood (Agatized/Silicified Wood)
Silicified Paleoxylon (primarily SiO2)
sedimentary
Agate with Fossil Bone
Silicified bone in Chalcedony (SiO2)
fossil
Tektite (Indochinite)
Tektite (High-silica impact glass)
igneous
Fossilized Horn Coral
Order Rugosa (Rugose Coral)
sedimentary
Black Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
igneous
Glass / Silicon Dioxide (Man-made)
SiO2 (Amorphous Silicon Dioxide)
Amorphous Solid
Sea Shell (Mollusk Shell)
Calcium Carbonate (Aragonite/Calcite)
fossil
Green cabochon gemstone, likely nephrite jade
Nephrite jade—interlocking amphibole fibers, chiefly tremolite-actinolite, Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂
gemstone
Quartzite
Quartzite (SiO2)
metamorphic
Tiger’s-eye (likely cabochon gemstone)
Quartz variety, chiefly SiO₂, with fibrous crocidolite-derived inclusions
gemstone
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Chert / Jasper
Cryptocrystalline Silica (SiO2)
sedimentary
Chert (Flint)
Microcrystalline Quartz or Cryptocrystalline Silica (SiO2)
sedimentary
Chert (Flint)
Microcrystalline Silicon Dioxide (SiO2)
sedimentary
Pyrite
Iron Sulfide (FeS2)
mineral
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Quartzite
Quartzite (SiO2)
metamorphic