Sandstone (with iron staining)
Quartz Arenite / Ferruginous Sandstone
sedimentary
Category
Man Made Composite
Browse man made composite specimens identified by the Rock Identifier community.
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Sandstone
Clastic Sedimentary Rock
sedimentary
Unidentified gray metallic object
Not determinable from the image; likely a metal screw or manufactured fastener rather than geological material
mineral
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Polished stromatolite (likely fossilized microbial mat)
Fossil stromatolite; chiefly microcrystalline quartz (SiO₂), commonly replacing carbonate
fossil
Rounded quartz pebble
Quartz (silicon dioxide, SiO₂)
mineral
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Polished orbicular jasper
Jasper, microcrystalline quartz (SiO₂), with iron oxides and other inclusions
mineral
Concrete-like aggregate surface with embedded rock fragments
Anthropogenic concrete or exposed aggregate; not a natural rock specimen
sedimentary
Red gemstone ring, likely garnet or synthetic ruby
Possibly almandine garnet (Fe₃Al₂(SiO₄)₃) or corundum/ruby (Al₂O₃); image alone cannot distinguish
gemstone
Polished greenstone pebble
Likely nephrite jade (tremolite–actinolite), though serpentine or greenstone is possible from appearance alone
metamorphic
Carved jasper bear figurine
Jasper, microcrystalline quartz (SiO₂), likely brecciated or orbicular jasper
mineral
Black-and-white agate geode pendant
Agate (microcrystalline quartz, SiO₂), likely a hollow geode slice with chalcedony and drusy quartz
mineral
Diamond
Carbon (C)
gemstone
Dumortierite in Quartz
Dumortierite (Al6O3(BO3)(SiO4)3) with Quartz (SiO2)
mineral
Flint
Silicon dioxide (SiO2)
sedimentary
Sandstone
Sedimentary Rock (Quartz Sandstone)
sedimentary
Diamond (or Cubic Zirconia simulant)
Carbon (C) - Diamond / Zirconium dioxide (ZrO2) - CZ
mineral
Limestone
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Quartzite
Quartzite (SiO2)
metamorphic
Multicolored beryl gemstone bracelet
Beryl, Be₃Al₂Si₆O₁₈; likely mixed aquamarine, morganite, heliodor, and green beryl beads
gemstone
Granite (Pegmatitic)
Phaneritic Felsic Igneous Rock
igneous
Chert (specifically White Chert or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Green iridescent glass cabochon or synthetic gemstone
Likely synthetic glass; possibly coated synthetic quartz or lab-created green gemstone
gemstone
Chert (varieties: Flint or Jasper)
Silicon dioxide (SiO2) / Microcrystalline Quartz
sedimentary
Pallasite Meteorite
Pallasite (Stony-Iron Meteorite)
meteorite
Diamond (Faceted)
Carbon (C)
gemstone
Native silver fragment (probable)
Silver, Ag; possibly silver-bearing sulfide or plated metal
mineral
Raw Diamond
Carbon (C)
gemstone
Diamond (in jewelry setting)
Adamantine Carbon (C)
mineral
Chert (Chocolate or Brown Flint)
Chert (SiO2)
sedimentary
Greenstone / serpentinite carving
Serpentinite, chiefly serpentine-group minerals (antigorite, lizardite, or chrysotile); exact identification requires testing
metamorphic
Diamond
Carbon (C)
gemstone
Pearl (with Peridot)
Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4
mineral
Chert (Flint/Chalcedony)
Silicon Dioxide (SiO2)
sedimentary
Sandstone (Red/Brown Variety)
Arenite (composed primarily of SiO2 with Fe2O3 iron oxide inclusions)
sedimentary
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Pyrite
Iron Sulfide (FeS2)
mineral
Diamond (or Diamond Simulant)
Carbon (C)
mineral
Green Slag Glass
Amorphous Silica / Glassy Blast Furnace Slag
Mineraloid (Industrial byproduct)
Swirled Agate Bead
Silicon Dioxide (SiO2)
mineral
Diamond
Natural Diamond (Carbon, C)
gemstone