Basalt
Basalt (containing plagioclase, pyroxene, and olivine)
igneous
Category
Mineraloid (Man Made)
Browse mineraloid (man made) specimens identified by the Rock Identifier community.
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Tumbled kambaba jasper (likely)
Kambaba jasper, a silica-rich microcrystalline quartz aggregate, commonly containing fossilized cyanobacterial structures and dark green amphibole/pyroxene minerals
sedimentary
Weathered sandstone boulder
Sandstone, chiefly quartz (SiO₂) with feldspar and iron-oxide cement
sedimentary
Polished green jasper cabochon (likely serpentine or nephrite imitation)
Jasper: microcrystalline quartz (SiO₂); green coloration may reflect chlorite, epidote, or iron minerals
metamorphic
Diamond
Carbon (C)
mineral
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Sandstone
Arenite (variable SiO2 composition)
sedimentary
Goldstone (aventurine glass)
Synthetic copper-bearing soda-lime glass; commonly sold as red goldstone
gemstone
Diamond
Carbon (C)
gemstone
Tumbled chalcedony or quartz pebble
Microcrystalline quartz, SiO₂ (likely chalcedony); exact identification is uncertain from the image
mineral
Turquoise-style beaded bracelet
Turquoise, hydrated copper–aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O; possibly dyed or composite beads
mineral
Botryoidal chalcedony with iron-oxide staining
Microcrystalline quartz (SiO₂), likely iron-oxide-bearing chalcedony
mineral
Likely tumbled epidote-bearing rock or green jasper
Epidote-group silicate, possibly in a jasper or serpentinite matrix
mineral
Smoky Quartz Cluster
Smoky Quartz (Silicon Dioxide - SiO2)
mineral
Weathered sedimentary rock, possibly sandstone
Indeterminate clastic sediment; probable quartz-rich sandstone
sedimentary
Chalk
Calcium Carbonate (CaCO3)
sedimentary
Metallic sulfide-bearing metamorphic rock
Likely graphitic schist or sulfide-rich schist, with possible pyrite/arsenopyrite and mica
metamorphic
Orange-yellow mineral fragment (possibly sulfur)
Unidentified; color suggests native sulfur (S), but the image is insufficient for confident identification
mineral
Red Quartzite
Quartzite (Metamorphic quartz sandstone)
metamorphic
Aragonite
Aragonite (Calcium Carbonate - CaCO3)
mineral
Diamond
Carbon (C)
mineral
Sandstone (Pebble)
Sandstone (SiO2 with matrix/cement)
sedimentary
Diamond
Carbon (C)
mineral
Black obsidian
Volcanic glass; predominantly silica-rich, noncrystalline SiO₂
igneous
Diamond (in a jewelry setting)
Cubic Carbon (C)
mineral
Likely weathered sandstone fragment
Sandstone, composed mainly of quartz (SiO₂) and feldspar grains in a clay, silica, or iron-oxide cement
sedimentary
Pearl
Aragonite (CaCO3 with conchiolin)
mineral
Pearl (Imitation or Cultured)
Calcium Carbonate (Aragonite/Calcite) - CaCO3
Mineraloid (Organic)
Pearl necklace
Pearl, primarily aragonite (CaCO₃) and conchiolin
gemstone
Diamond (faceted)
Diamond (Pure Carbon, C)
mineral
Quartzite
Metamorphic quartz rock (SiO2)
metamorphic
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Diamond
Carbon (C)
gemstone
Concrete or asphalt-like aggregate surface with a dark fragment
Uncertain; likely artificial concrete containing mixed lithic aggregate, not a natural rock
sedimentary
Pearl
Calcium Carbonate (CaCO3) with Conchiolin
mineral
Sandstone
Arenite (specifically sublithic or quartz arenite)
sedimentary
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Pyrite
Iron Sulfide (FeS2)
mineral
Sandstone
Arenite (SiO2 primarily)
sedimentary
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Tumbled green glassy mineral, possibly aventurine or fluorite
Uncertain; likely quartz variety (aventurine quartz, SiO₂) or green fluorite (CaF₂)
mineral
Chert (Arrowhead Shard)
Microcrystalline silica (SiO2)
sedimentary