Sapphire
Corundum (Al₂O₃) with trace elements causing color variations.
Mineral
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.
Goldstone (with Tiger's Eye and Quartz)
Aventurine glass (Synthetic SiO2 with Cu inclusions)
mineral
Felted Quartz / Chlorite Quartz
Chlorite included Quartz (SiO2 + (Mg,Fe)3(Si,Al)2O5(OH)4)
mineral
Quartzite (River Pebble)
Quartzite (composed primarily of Silica, SiO2)
metamorphic
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Granite
Granite (a phaneritic intrusive igneous rock consisting mainly of quartz, alkali feldspar, and plagioclase)
igneous
White Quartzite
Quartzite (primarily SiO2 - Silicon Dioxide)
metamorphic
Mica-rich Sandstone or Micaceous Schist Weathering
Micaceous Schist (Muscovite-Quartz composition)
Metamorphic or Sedimentary depending on local grade
Quartzite
Quartzite (primarily SiO2)
metamorphic
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide (SiO2) with Hematite/Goethite inclusions
mineral
Quartzite (River Cobble)
Quartzite (SiO2)
metamorphic
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Diorite (River Pebble)
Intermediate plutonic igneous rock
igneous
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide (SiO2) with iron oxide inclusions/staining (Limonite/Hematite)
Mineral
Ironstone Concretion
Siderite or Hematite-bonded Concretion
sedimentary
Chert (often called Flint or Agate nodule)
Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Flint)
Microcrystalline quartz (SiO2)
sedimentary
Chert (specifically Red Chert or Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Dyed Quartz (often sold as 'Blue Quartz' or 'Blue Agate')
Silicon Dioxide (SiO2) with artificial pigment
mineral
Bismuth Crystal
Bismuth (Bi)
mineral
Chalcanthite (Likely Synthetic/Lab-Grown)
Hydrated copper(II) sulfate (CuSO4·5H2O)
mineral
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
mineral
Quartz / Quartzite
Quartzite (primarily Silicon Dioxide, SiO2)
metamorphic
Chrysocolla in Malachite
Cu2CO3(OH)2 (Malachite) / Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Chrysocolla)
mineral
Synthetic Costume Glove (Paws)
Polyethylene terephthalate (Polyester) & Polyurethane blend
Non-geological / Man-made textile
Garnet Beads
Garnet Group (complex nesosilicates, e.g., Almandine Fe3Al2(SiO4)3)
Mineral
Apache Tear
Obsidian (Hydrated Silica Rich Volcanic Glass)
igneous
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
mineral
Mica Schist with Pyrite
Muscovite/Biotite Schist with Iron Sulfide (FeS2)
metamorphic
River Rocks (Black)
Various lithologies (e.g., basalt, chert, obsidian for black varieties), mechanically rounded clasts
Sedimentary
Chrysoprase
Chalcedony (cryptocrystalline SiO2 variety)
Mineral
Green Aventurine
Silicon dioxide (SiO2) with inclusions of Fuchsite mica
metamorphic
Pink Granite
Phaneritic Felsic Intrusive Igneous Rock
igneous
Blue Goldstone
Aventurine Glass (Silicon Dioxide infused with Cobalt/Copper)
Synthetic (Man-made Glass)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Black Spinel
Magnesium Aluminum Oxide (MgAl2O4)
mineral
Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx')
Calcite (Calcium Carbonate, CaCO3)
Sedimentary
Crinoid Fossil Stem Segment
Class Crinoidea (Echinodermata)
sedimentary
Fuchsite
Fuchsite (a variety of Muscovite mica, K(Al,Cr)2(AlSi3O10)(OH)2)
mineral
Blue Goldstone
Aventurine Glass (Silicon Dioxide with metal inclusions)
man-made glass mineral simulant
Quartzite
Quartzite (SiO2)
metamorphic
Amethyst
SiO2 (Silicon Dioxide)
Mineral