Polished black stone pendant
Likely black obsidian or black tourmaline; exact identification is uncertain from the photograph
mineral
Category
Man Made
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Fossil shark tooth in sediment
Likely fossilized shark tooth, possibly *Carcharhinus* or *Otodus*; exact identification requires the tooth’s full morphology and locality
fossil
Unidentified polished dark gemstone cabochon
Possibly hematite, obsidian, jet, or dark agate; image insufficient for a definitive identification
gemstone
Likely banded obsidian or dark volcanic glass
Obsidian, predominantly rhyolitic volcanic glass (SiO₂-rich), possibly with devitrified bands and phenocrysts
igneous
Yellow Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Chrysocolla
Hydrated copper phyllosilicate, (Cu,Al)2H2Si2O5(OH)4·nH2O
mineral
Granite
Felsic intrusive igneous rock
igneous
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Pink Granite (Alkali-feldspar Granite)
Felsic intrusive igneous rock (composition: KAlSi3O8, SiO2, NaAlSi3O8)
igneous
Sandstone (Ferruginous)
Arenite (SiO2 with Fe2O3 inclusions)
sedimentary
Sandstone
Arenite (SiO2 based)
sedimentary
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Small metallic-looking mineral/rock fragment
Indeterminate from image; possibly galena, hematite, or metallic slag
mineral
Small dark rock fragment
Uncertain; possibly weathered basalt or slag
mineral
Corundum (Sapphire variant)
Aluminium oxide (Al2O3)
mineral
Precious Coral (Red Coral)
Corallium rubrum (Calcium Carbonate, CaCO3)
mineral
Diamond ring
Diamond, crystalline carbon (C)
gemstone
Riverstone (Sandstone Pebble)
Arenite (SiO2 with various lithic fragments)
sedimentary
Unidentified gray metallic object
Not determinable from the image; likely a metal screw or manufactured fastener rather than geological material
mineral
Coquina
Biogenic Limestone (CaCO3)
sedimentary
Polished orbicular jasper (likely ocean jasper)
Siliceous microcrystalline quartz/chalcedony with iron-oxide and volcanic inclusions; commonly called ocean jasper
mineral
Tourmalinated quartz point
Quartz (SiO₂) with black tourmaline (schorl, NaFe²⁺₃Al₆(BO₃)₃Si₆O₁₈(OH)₄) inclusions
mineral
Coal (Bituminous Coal)
Caustobiolith / Sedimentary Rock
sedimentary
Fossiliferous Limestone with Crinoid Stem
Sedimentary Rock with Crinoidea Fossil
fossil
Tumbled chalcedony or quartz pebble
Microcrystalline quartz (SiO₂), likely orange chalcedony/carnelian
mineral
Jasper
Silicon dioxide (SiO2) with impurities
sedimentary
Chert (Chert / Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone
Arenite (SiO2 based clastic rock)
sedimentary
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Chert / Flint
Cryptocrystalline quartz (SiO2)
sedimentary
Red Quartzite
Quartzite (Metamorphic quartz sandstone)
metamorphic
Diamond in Kimberlite
Diamond in Kimberlite Matrix (Diamond: C, Kimberlite: complex Potassic Peridotite)
igneous
Chert (Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Pearl
Aragonite / Calcium Carbonate (CaCO3)
mineraloid
Granite
Phaneritic Felsic Intrusive Igneous Rock
igneous
Diamond (Cluster Ring)
Carbon (C)
mineral
Granite
Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8)
igneous
Chert (specifically Jasper or Flint)
Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (often called Flint)
Chert (Microcrystalline or cryptocrystalline Silica, SiO2)
sedimentary
Flower Agate
Chalcedony (SiO2) with inclusions
mineral
Basalt
Basalt (Mafic volcanic rock)
igneous