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Indeterminate
Category
Mineral Based Composite
Browse mineral based composite specimens identified by the Rock Identifier community.
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Breccia
Breccia
sedimentary
Decorative gemstone-chip jewelry (likely turquoise, coral, and assorted beads)
Predominantly turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O; other pieces appear to be dyed coral or red stone, and possibly shell/metal components
gemstone
Rose Quartz
Silicon Dioxide (SiO2) with trace titanium, iron, or manganese
mineral
Sandstone
Arenite
sedimentary
Carved turquoise arrowhead/pendant
Turquoise, hydrated copper aluminum phosphate — CuAl₆(PO₄)₄(OH)₈·4H₂O
gemstone
Amethyst (vibrant lilac/purple variety)
Silicon Dioxide (SiO2) with iron impurities
mineral
Polished malachite
Malachite (Cu₂CO₃(OH)₂), a hydrated copper carbonate hydroxide
mineral
Polished malachite slab
Malachite, Cu₂CO₃(OH)₂; likely polished and possibly resin-stabilized
mineral
Biotite Mica
Biotite (K(Mg,Fe)3AlSi3O10(OH,F)2)
mineral
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Iron Slag
Anthropogenic Iron oxide/Silicate composite
Mineral-like byproduct (Technogenic)
Sandstone (River Rock)
Arenite (SiO2 based sedimentary rock)
sedimentary
Small tumbled blue-green stone, possibly chrysocolla or turquoise
Indeterminate copper-bearing mineral; possible chrysocolla (Cu₂H₂Si₂O₅(OH)₄·nH₂O) or turquoise (CuAl₆(PO₄)₄(OH)₈·4H₂O)
mineral
Polished chalcedony (likely sagenite or included agate)
Microcrystalline quartz, SiO₂, with iron-oxide and possibly rutile/goethite inclusions
gemstone
Sandstone
Arenite (SiO2 based typically)
sedimentary
Sandstone
Arenite (SiO2 based typically)
sedimentary
Sandstone
Arenite (SiO2 based with cement)
sedimentary
Black Spinel
Magnesium Aluminum Oxide (MgAl2O4)
mineral
Chalcedony (Grey/White Agate)
Silicon Dioxide (SiO₂)
mineral
Turquoise cabochon
Turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O; likely stabilized or matrix-bearing
mineral
Sandstone (Quartzose)
Arenite (SiO2 based typically)
sedimentary
Hag Stone
Perforated Sedimentary Rock
sedimentary
Painted Sandstone
Sandstone (clastic sedimentary rock) with acrylic/artistic coating
sedimentary
Sandstone
Arenite (SiO2 based typically)
sedimentary
Weathered quartz-rich pebble
Likely quartz-bearing vein rock; exact identification requires testing
mineral
Fossilized Shark Tooth
Bioapatite (Calcium Hydroxyapatite) replacement
mineral
Mixed Gemstone and Mineral Collection
Silicon Dioxide (SiO2) based minerals and others
mineral
Sandstone
Arenite (SiO2 dominant)
sedimentary
Moss Agate
Silicon Dioxide with inclusions (SiO2)
mineral
Polished yellow jasper cabochon
Jasper, microcrystalline quartz (SiO₂) with iron-oxide and clay inclusions
metamorphic
Chert with Chalcedony/Quartz Vug
Cryptocrystalline Silica (SiO2)
sedimentary
Fossilized Crinoid Stem Cross-Section
Crinoidea
fossil
Sandstone
Arenite (Sedimentary rock composed of sand-sized grains)
sedimentary
Otodus Shark Tooth
Otodus obliquus
fossil
Granite Thin Section
Granitic rock (Phaneritic texture)
igneous
Red Sandstone
Arenite (SiO2 based with Fe2O3)
sedimentary
Sandstone
Arenite (SiO2 based typically)
sedimentary
Sandstone (Siltstone or Fine-grained)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Sandstone
Arenite (typically SiO2 based)
sedimentary
Polished pietersite-like brecciated jasper
Silicified chalcedony/jasper aggregate, primarily SiO₂; exact material uncertain from image
metamorphic
Fossil / Permineralized Bone
Tyrannosaurus rex fossil (Hydroxylapatite replaced by various minerals)
sedimentary