Gastropod Fossil (Snail Internal Mold)
Gastropoda; internal mold (steinkern), often composed of Calcium Carbonate (CaCO3) or Silica (SiO2)
sedimentary
Category
Organic (If Resin) Or Synthetic (If Glass); Simulating Sedimentary Or Metamorphic (For Natural Stones)
Browse organic (if resin) or synthetic (if glass); simulating sedimentary or metamorphic (for natural stones) specimens identified by the Rock Identifier community.
Schist
Mica Schist (Group of medium-grade metamorphic rocks)
metamorphic
Optical Calcite (Iceland Spar)
Calcite (Calcium Carbonate, CaCO3)
mineral
Cinnabar in Matrix
Cinnabar (Mercury(II) sulfide, HgS)
mineral
Granite Pebble
Granite
igneous
Clear Quartz crystals on a Matrix base (Geode fragment)
Silicon Dioxide (SiO2)
mineral
Schist
Mica Schist (contains muscovite/biotite and quartz)
metamorphic
Iron-stained Quartz
Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3/FeO(OH))
mineral
Ferrous Slag
Fused calcium-iron silicates (Industrial Slag)
Anthropogenic/Industrial byproduct
Jasper (Iron-rich Microcrystalline Quartz)
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Slag (Anthropogenic Glass/Iron byproduct)
Ferro-silicate Slag
Anthropogenic (Man-made)
Metal Chain (Likely Steel or a Steel Alloy)
Steel (primarily iron and carbon); specific alloy unknown
Man-made Object (Metal/Alloy)
Fossiliferous Limestone
Limestone with fossil inclusions (CaCO3)
sedimentary
Biotite (Black Mica)
Biotite - K(Mg,Fe)3AlSi3O10(F,OH)2
mineral
Quartz (likely a weathered/tumbled piece)
Quartz (SiO₂)
Mineral
Amber
Succinite (specifically Baltic Amber) - Formula: C10H16O (approximate)
Organic Mineraloid
Quartz with Mica inclusion
Silicon Dioxide (SiO2) with Muscovite/Biotite inclusions
igneous
Slag (Industrial Glassy Byproduct)
Anthropogenic silicate byproduct (Slag)
Mineral-like byproduct (often mistaken for igneous rock or meteorite)
Obsidian
Obsidian (Volcanic Glass)
igneous
Tiger's Eye (Polished Point/Tower)
SiO2 (Silicon Dioxide) with included crocidolite fibers
Mineral (Metamorphic pseudomorph)
Travertine (Tufa)
Chemical Sedimentary Limestone (CaCO3)
sedimentary
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Conglomerate
Clastic sedimentary rock (Psephite)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Favosites (Honeycomb Coral Fossil)
Favosites (Genus of extinct tabulate coral)
sedimentary
Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx')
Calcite (Calcium Carbonate, CaCO3)
Sedimentary
Greenstone or Chlorite Schist
Greenschist / Chlorite schist
metamorphic
Mica Schist
Mica Schist (Complex Silicate Rock)
metamorphic
Quartz Vein with Iron Staining
Silicon Dioxide (SiO2)
mineral
Calcite
Calcium Carbonate (CaCO3)
mineral
Soapstone (Talc-Schist)
Steatite (composed primarily of Talc: Mg3Si4O10(OH)2)
metamorphic
Orthoclase (Potassium) Feldspar in Quartz
KAlSi3O8 (Potassium Aluminum Silicate)
igneous
Geode Nodules / Chalcedony Geode
Silicon Dioxide (SiO2) - Amorphous to Cryptocrystalline Quartz
sedimentary
Ferruginous Quartz
Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3/FeO(OH))
mineral
Amygdaloidal Basalt
Amygdaloidal Basalt with Secondary Infilling (e.g., Agate, Quartz, or Zeolite)
igneous
N/A - Man-made object (Jewelry Chain)
Antiqued or Oxidized Metal Chain (often Steel or Brass)
Mineral (processed metal)
Pebble (Likely Basalt or Siltstone)
Clastic sedimentary rock or mafic volcanic rock
Igneous or Sedimentary
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Blue Sea Glass
Amorphous Silica (Anthropogenic glass)
not a rock (man-made origin)
Pegmatitic Granite
Granite (Alkali-feldspar granite) with Quartz and Orthoclase
igneous
Chalcedony (River Stone)
Microcrystalline Quartz (SiO2)
mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Mineral