Sandstone
Arenite (SiO2, often with CaCO3 or Fe2O3 cement)
sedimentary
Category
Not A Rock (Man Made Polymer)
Browse not a rock (man made polymer) specimens identified by the Rock Identifier community.
Learn about Not A Rock (Man Made Polymer) in the encyclopedia
View all →
Hematite Beads
Hematite (Fe2O3)
Mineral
Blue Sapphire (Synthetic or Man-made Glass Imitation)
Corundum (Al2O3) if natural; Lead-glass or Spinal if synthetic
mineral
Terracotta (Man-made ceramic brick fragment)
Baked clay / High-iron ceramic (Silicate-based ceramic)
Anthropogenic material (Man-made sedimentary mimic)
Note: Item is a Synthetic/Man-made Object
Titanium-coated Stainless Steel (Fe-Cr-Ni-Ti)
Non-geological
Opalite (a synthetic glass, often confused with Opal)
Silicon dioxide glass (SiO2nH2O, for natural opal)
Synthetic (glass)
Dyed Quartz Geode
Silicon Dioxide (SiO2) with artificial pigment
mineral
Basalt
Basalt
Igneous
Gabbro
Gabbro
igneous
Blue goldstone
Man-made aventurine glass containing metallic copper particles; not a natural mineral
mineral
Likely polished quartz or glass-like mineral cabochon
Probably quartz (SiO₂), though the image cannot exclude man-made glass
mineral
Green Glass Slag
Amorphous Silicon Dioxide (SiO2) with metal oxide impurities
mineraloid (man-made)
Slate
Metamorphic Pelitic Rock
metamorphic
Red jasper
Jasper, a microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides
mineral
Tumbled jasper pebble
Jasper, an opaque microcrystalline variety of quartz (SiO₂), commonly colored by iron oxides and hydroxides
mineral
Blue glassy mineral specimen, possibly dyed or synthetic
Uncertain; possible blue fluorite (CaF₂), dyed chalcedony, or man-made glass
mineral
Pink feldspar-rich granite
Granite, composed chiefly of quartz, potassium feldspar, and plagioclase, with minor mica or other minerals
igneous
Amber
Succinite (specifically for Baltic amber); chemical formula approximately C10H16O
Mineraloid
Polished red jasper
Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides
mineral
Lava Rock (Dyed)
Basalt / Volcanic scoria
igneous
Pumice
Pumice (Vitreous volcanic rock)
igneous
Druzy quartz on matrix
Quartz (SiO₂), microcrystalline crystal coating
mineral
Diamond Druzy (Crystalline Diamond)
Carbon (C)
mineral
Man-made Jewelry Charm (Enameled Metal)
Not a natural mineral; composed of base metal alloy (likely zinc or brass) and epoxy resin/enamel.
Synthetic / Manufactured Artifact
Cullet Glass (Man-made Glass Slag)
Amorphous Silica (SiO2) with chemical additives
Mineraloid
Tumbled red jasper
Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides
mineral
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Grey Chalcedony
Silicon Dioxide (SiO2)
mineral
Amber
Succinite (amorphous organic polymer)
mineral
Cobalt Glass Slug (Man-made Glass)
Amorphous Silica with Cobalt Oxide (SiO2 + CoO)
mineraloid
Green Agate
Silicon dioxide (SiO₂)
mineral
Blue Lace Agate
Chalcedony (SiO2) with trace inclusions
mineral
Orange glassy slag (industrial by-product)
Iron-rich silicate glass; composition varies, commonly Fe–Ca–Al silicate
mineral
Turquoise
Turquoise, hydrated copper–aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O
gemstone
Pearls
Pearl: biomineralized aragonite (CaCO₃) and conchiolin
gemstone
Turquoise
Hydrated phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O
mineral
Slate
Metamorphic Pelitic Rock
metamorphic
Red glassy cabochon, likely synthetic ruby or red glass
Uncertain; possible synthetic corundum (Al₂O₃, chromium-colored) or man-made glass
gemstone
Tumbled opalite (likely synthetic glass)
Opalite; typically man-made opalescent soda-lime glass, not a recognized mineral species
gemstone
Goldstone (Red/Brown)
Aventurine Glass (SiO2 with Copper inclusions)
Mineral (Man-made glass)
Coquina
Bioclastic Limestone (composed primarily of CaCO3)
sedimentary
Chert (likely chalcedony-rich flint)
Microcrystalline quartz, SiO₂ (quartz/chalcedony)
sedimentary