Sandstone (Red/Brown Variety)
Arenite (composed primarily of SiO2 with Fe2O3 iron oxide inclusions)
sedimentary
Category
Man Made Byproduct (Often Mistaken For Obsidian Or Emerald)
Browse man made byproduct (often mistaken for obsidian or emerald) specimens identified by the Rock Identifier community.
Dumortierite Quartz
Dumortierite (Al7BCuO15)
metamorphic
Marble
Marble (metamorphosed limestone/dolostone). Predominantly composed of Calcite (CaCO3) for marble derived from limestone, or Dolomite (CaMg(CO3)2) for marble derived from dolostone.
Metamorphic Rock
Pink Cubic Zirconia (CZ)
Zirconium Dioxide (ZrO2)
mineral (synthetic)
Chrome Diopside
Diopside (Magnesium Calcium Silicate) - CaMgSi2O6 + Cr
mineral
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Fuchsite on Quartzite
Muscovite (Chromium-bearing) K(Al,Cr)2(AlSi3O10)(OH)2
metamorphic
Obsidian (Gold Sheen)
Obsidian (SiO2 + impurities)
igneous
Fuchsite Schist
Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2) in Schist
metamorphic
Black Obsidian
Volcanic Glass (Amorphous Silicon Dioxide, SiO2)
igneous
Fuchsite
K(Al,Cr)2(AlSi3O10)(OH)2 (Chromium-rich Muscovite)
mineral
Beryl (Aquamarine) in Matrix
Beryllium aluminum silicate (Be3Al2(SiO3)6)
mineral
Pyrite in Quartzite/Graphite Matrix
Iron Sulfide (FeS2)
Mineral
Ferruginous Sandstone (Ironstone Conglomerate fragments)
Ferruginous clastic sedimentary rock (SiO2 cemented by Fe2O3)
sedimentary
Man-made Metal Pin (Non-geological)
Antimony-Lead Alloy or Zinc/Brass Base with Electroplating
Metal Alloy / Manufactured Artifact
Fuchsite in Quartz
K(Al,Cr)2(AlSi3O10)(OH)2 in SiO2
metamorphic
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Scoria (with likely iron oxidation)
Scoria (Basaltic Scoria)
igneous
Man-made Synthetic Material (Plastic/Composite)
Acrylonitrile Butadiene Styrene (ABS) or High-Impact Polystyrene (HIPS)
Non-geological / Synthetic
Pyrite
Iron Disulfide (FeS2)
mineral
Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
mineral
Artisanal Glass Beads (Simulated Goldstone or Aventurine Glass)
Silicon Dioxide (SiO2) with metallic inclusions
man-made material
Green Rutilated Quartz
Silicon Dioxide with Actinolite inclusions (SiO2 + Ca2(Mg,Fe)5Si8O22(OH)2)
mineral
Rhyolite
Rhyolite (Extrusive Igneous Rock)
igneous
Quartz (Microcrystalline/Chert)
Silicon Dioxide (SiO2)
mineral
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
mineral
Chrysocolla Chalcedony
Hydrated Copper Phyllosilicate (Cu,Al)2H2Si2O5(OH)4 + SiO2
mineral
Dalmatian Jasper
Peralkaline rhyolite with Arfvedsonite inclusions
igneous
Diamond (or Diamond Simulant)
Carbon (C)
mineral
Raw Emerald in Matrix
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities
mineral
Sea Glass (White/Clear)
Amorphous Silica (Alkali-Lime-Silica Glass), SiO2 + Na2O + CaO
Anthropogenic (Man-made product subject to geological processes)
Pyrite with Iron Oxides (Fool's Gold in Matrix)
Iron Sulfide (FeS2)
mineral
Jade (Nephrite or Jadeite)
Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2) or Jadeite (Na(Al,Fe3+)Si2O6)
Mineral
Chrysocolla
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4 nH2O
mineral
Rainbow Hematite (Titanium Coated)
Iron(III) oxide (Fe2O3) with Titanium/Metal Oxide coating
mineral
Black Obsidian
Volcanic Glass (Amorphous Silicon Dioxide SiO2)
Igneous
Aura Quartz
Titanium/Titanium-Gold treated Silicon Dioxide (SiO2)
mineral
Ruby
Corundum (Al₂O₃) with Chromium (Cr)
Mineral (gemstone)
Concretion
Various mineral compositions, typically carbonate or iron oxide cemented sediment
Sedimentary
Mixed Gemstone Beaded Jewelry
Various minerals (e.g., Quartz varieties like Rose Quartz, Amethyst; Peridot; Garnet; etc.)
Mineral
Chert (variations include Flint/Novaculite)
Chert (formula: SiO2)
sedimentary
Amethyst (Chevron or Banded Amethyst)
Silicon Dioxide (SiO2) with iron impurities
mineral