Pearl
Calcium Carbonate (CaCO3) with Conchiolin
mineral
Category
Antropogenic (Man Made)
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Sandstone
Arenite (specifically sublithic or quartz arenite)
sedimentary
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Pyrite
Iron Sulfide (FeS2)
mineral
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Concrete or asphalt-like aggregate surface with a dark fragment
Uncertain; likely artificial concrete containing mixed lithic aggregate, not a natural rock
sedimentary
Tumbled epidote-bearing rock (likely epidote–quartz–feldspar aggregate)
Epidote-rich metamorphic rock; minerals likely epidote (Ca₂(Al,Fe)₃Si₃O₁₂(OH), quartz, feldspar, and dark amphibole/biotite)
metamorphic
Sandstone
Arenite (SiO2 primarily)
sedimentary
Nacre (Mother of Pearl)
Nacre (Biogenic Aragonite/Calcite composite, CaCO3)
mineral
Chert (Arrowhead Shard)
Microcrystalline silica (SiO2)
sedimentary
Quartzite
Metamorphic Quartz Arenite
metamorphic
Sandstone (likely Fossiliferous)
Arenite / Fossiliferous Sandstone (SiO2 composition)
sedimentary
Tumbled green glassy mineral, possibly aventurine or fluorite
Uncertain; likely quartz variety (aventurine quartz, SiO₂) or green fluorite (CaF₂)
mineral
Chert (flint) fragment
Microcrystalline quartz (SiO₂), commonly called chert; “flint” is a variety of chert
sedimentary
Diamond
Diamond (Pure Carbon, C)
mineral
Coquina
Bioclastic Limestone (composed primarily of CaCO3)
sedimentary
Rounded granite cobble
Granite, a coarse-grained felsic intrusive igneous rock composed chiefly of quartz, feldspar, and mica
igneous
Diamond (Cluster Ring)
Carbon (C)
mineral
Diamond
Carbon (C)
mineral
Chert (Chert / Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Diamond in Kimberlite
Diamond (C in Kimberlite Matrix)
igneous
Pearl
Calcium Carbonate (mostly Aragonite), CaCO3 (with conchiolin)
mineral
Rough Diamond
Diamond (pure Carbon, C)
mineral
Diamond
Native Carbon (C)
mineral
Diamond
Carbon (C)
mineral
Likely clear quartz crystal (possibly cut/polished quartz or glass imitation)
Quartz, silicon dioxide (SiO₂)
mineral
Sandstone
Sedimentary Rock (Quartz arenite)
sedimentary
Quartzite
Quartzite (Metamorphic Quartz Sandstone)
metamorphic
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Rough Diamond
Pure Carbon (C)
mineral
Sandstone (with iron staining)
Quartz Arenite / Ferruginous Sandstone
sedimentary
Sandstone
Clastic Sedimentary Rock
sedimentary
Fossilized Shark Tooth (Fragment)
Elasmobranchii gen. et sp. indet. (Calcium Phosphate / Apatite fossil)
fossil
Dark rounded pebble, likely basalt or slag
Probable fine-grained mafic rock; possibly basalt (plagioclase–pyroxene) or industrial iron/steel slag
igneous
Mounted faceted gemstone ring
Likely diamond (carbon, C), though the image is insufficient for definitive identification
gemstone
Bituminous Coal (with Anthracite or Vitrinite inclusion)
Organic-rich Sedimentary Rock (Carboniferous classification)
sedimentary
Tree Agate
Chalcedony (SiO2)
gemstone
Likely blue glass or synthetic gemstone jewelry
Uncertain; possibly synthetic spinel, cubic zirconia, or blue glass
gemstone
Limestone
Calcareous sedimentary rock (CaCO3)
sedimentary
Rough Diamond
Diamond (pure Carbon, C)
mineral
Pumice
Vesicular volcanic glass, typically rhyolitic to dacitic; mainly silica-rich volcanic glass with feldspar and minor quartz or pyroxene
igneous
Sandstone
Sandstone (Quartz-rich Arenite / SiO2)
sedimentary