Likely weathered pebble or mineral fragment
Indeterminate; possibly quartz-rich stone, iron-stained feldspar, or a small chert fragment
mineral
Category
Man Made (Synthetic Rock)
Browse man made (synthetic rock) specimens identified by the Rock Identifier community.
Learn about Man Made (Synthetic Rock) in the encyclopedia
View all →
Sandstone
Sandstone (Quartz-rich Arenite / SiO2)
sedimentary
Red faceted gemstone, likely synthetic ruby or red glass
Ruby: corundum, aluminum oxide (Al₂O₃), chromium-colored; identity cannot be confirmed visually
gemstone
Greenstone / serpentinite carving
Serpentinite, chiefly serpentine-group minerals (antigorite, lizardite, or chrysotile); exact identification requires testing
metamorphic
Diamond
Natural Diamond (Carbon, C)
gemstone
Diamond (Cut Gemstone)
Carbon (C)
gemstone
Granite
Intrusive Felsic Igneous Rock (primarily Quartz and Feldspar)
igneous
Geode (Unopened)
Quartz Geode (SiO2) / Chalcedony Concretion
mineral
Synthetic Sapphire and Ion-X Glass
Single-crystal Alumina (Al2O3) and Ion-strengthened Aluminosilicate Glass
mineral
Ruby (or potential synthetic/imitation)
Corundum (Al2O3)
gemstone
Polished orbicular jasper (likely ocean jasper)
Siliceous microcrystalline quartz/chalcedony with iron-oxide and volcanic inclusions; commonly called ocean jasper
mineral
Tumbled gray chalcedony (likely agate or quartzite)
Microcrystalline quartz, SiO₂ (chalcedony)
mineral
Sandstone
Arenite (SiO2 primarily)
sedimentary
Coquina and Oyster Fossil Rock
Coquina limestone (Calcium Carbonate, CaCO3) containing fossilized Crassostrea / bivalve shells
fossil
Tektite
Natural impact glass
meteorite
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Flint (chert) hand axe
Cryptocrystalline silica (SiO₂), worked into a bifacial stone tool
sedimentary
Note: Item is not a geological specimen
Polyester mesh and Ethylene-vinyl acetate (EVA) polymer
Synthetic / Anthropogenic Material
Chert
Microcrystalline quartz (SiO2)
sedimentary
Coquina (Fossiliferous Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Yellow faceted gemstone, likely citrine or yellow beryl
Quartz (SiO₂), if citrine; beryl (Be₃Al₂Si₆O₁₈), if heliodor
gemstone
Chert
Microcrystalline quartz (SiO2)
sedimentary
Granodiorite
Granodiorite (Quartz + Plagioclase + Alkali Feldspar + Biotite/Hornblende)
igneous
Pink Granite
Phaneritic Felsic Intrusive Igneous Rock
igneous
Slate
Metamorphic pelitic rock
metamorphic
Yooperlite (Syenite clast containing fluorescent Sodalite)
Sodalite-bearing Syenite
igneous
Chert (Chalcedony/Agate)
Microcrystalline Quartz (SiO2)
sedimentary
Flint
Silicon dioxide (SiO2)
sedimentary
Grey Granite
Phaneritic Felsic Intrusive Igneous Rock
igneous
Asphalt (Bituminous Concrete)
Composite material (bitumen binder with mineral aggregate)
man-made rock (technosol)
Probable amber fragment
Amber (fossilized plant resin; chiefly amorphous organic resin, commonly dominated by succinite)
gemstone
Likely tumbled epidote-bearing rock or green jasper
Epidote-group silicate, possibly in a jasper or serpentinite matrix
mineral
Diorite (River Pebble)
Intermediate plutonic igneous rock
igneous
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
metamorphic
Sandstone
Arenite (composed primarily of Quartz: SiO2)
sedimentary
Ametrine
SiO2 (Silicon Dioxide with iron impurities)
gemstone
Moissanite
Silicon Carbide (SiC)
mineral
Blue cabochon ring stone, likely sapphire or synthetic blue corundum
Corundum (Al₂O₃), possibly chromium/iron-titanium-bearing sapphire
gemstone
Lapis Lazuli
Lapis lazuli (complex rock; primarily Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
metamorphic
Anthracite Coal
Anthracite (Carbon-based organic sedimentary rock transitioned to metamorphic)
metamorphic
Diamond (or Diamond Simulant)
Carbon (C)
mineral
Diamond in Kimberlite
Diamond (C in Kimberlite)
igneous