Possible basalt or iron-rich slag
Basalt (tentative; identification uncertain from image)
igneous
Category
Man Made Material
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Coquina
Bioclastic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Mother of Pearl (Nacre)
Calcium Carbonate (primarily aragonite, with conchiolin)
Organic Gemstone/Biomineral
Blue chalcedony bead necklace
Chalcedony, microcrystalline quartz (SiO₂), commonly blue-dyed or blue-gray natural chalcedony
gemstone
Marble
Recrystallized Calcite (CaCO3)
metamorphic
Banded agate pendant (likely carnelian or brown-and-white chalcedony agate)
Agate, a banded variety of chalcedony; microcrystalline quartz, SiO₂, with iron-oxide coloration
gemstone
Diamond
Carbon (C)
gemstone
Chert (Flinty variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx')
Calcite (Calcium Carbonate, CaCO3)
Sedimentary
Synthetic Faux Fur Fursuit
Polyacrylonitrile / Polyester (Synthetic Textile)
not a rock (synthetic material/costume)
Basalt
Basalt
igneous
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Diamond
Carbon (C)
gemstone
Vesicular basalt (likely scoria)
Basaltic scoria; predominantly plagioclase, pyroxene, and olivine in a mafic volcanic glass/microcrystalline matrix
igneous
Chert (Flint)
Chert (Microcrystalline or cryptocrystalline Quartz - SiO2)
sedimentary
Chert (specifically Zebra Chert/Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (Flint)
Microcrystalline quartz (SiO2)
sedimentary
Slag
Anthropogenic Vitrification Product / Silicate Slag
Anthropogenic (Man-made industrial byproduct)
Aragonite Star Cluster
Aragonite (Calcium Carbonate, CaCO3)
mineral
Diamond
Carbon (C)
mineral
Porous limestone (likely fossiliferous or weathered limestone)
Calcite-rich limestone; chiefly calcium carbonate (CaCO₃)
sedimentary
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Flint
Silicon Dioxide (SiO2) - Chert variety
sedimentary
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Asphalt aggregate
Human-made bituminous asphalt containing crushed silicate rock aggregate
sedimentary
Granite
Phaneritic plutonic rock (SiO2 typically >69%)
igneous
Megalodon Shark Tooth
Otodus megalodon
fossil
Tumbled iron-rich stone, likely hematite-bearing jasper
Jasper (microcrystalline quartz, SiO₂) with iron oxides, chiefly hematite/goethite
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Diorite
Diorite (Intermediate intrusive igneous rock)
igneous
Green agate/chalcedony bead necklace
Microcrystalline quartz (SiO₂), likely green chalcedony or dyed green agate
gemstone
Lapis lazuli and green-blue chalcedony jewelry
Lapis lazuli: lazurite-bearing metamorphic rock, chiefly lazurite (Na₃Ca(Al₃Si₃O₁₂)S) with calcite and pyrite; second stone: likely chrysoprase or green-blue chalcedony (microcrystalline quartz, SiO₂)
gemstone
Industrial Slag
Anthropogenic Vitreous Slag
igneous
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Mixed quartz gemstone bead bracelet
Quartz, silicon dioxide (SiO₂), in varieties including smoky quartz, amethyst, rutilated quartz, and possibly tourmalinated quartz
gemstone
Dyed turquoise-colored lava stone beads
Vesicular basalt (scoria), commonly sold as dyed lava rock
igneous
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Coquina Limestone
Coquina (Biogenic Limestone)
sedimentary
Chert (Iron-stained)
Chert (Microcrystalline and Cryptocrystalline Quartz, SiO2)
sedimentary
Iron-rich banded quartzite / jaspilite
Banded iron formation (BIF), chiefly quartz (SiO₂) and iron oxides (hematite, Fe₂O₃; magnetite, Fe₃O₄)
metamorphic
Unidentified gray metallic object
Not determinable from the image; likely a metal screw or manufactured fastener rather than geological material
mineral
Chert (Nodular or Massive Variety)
Cryptocrystalline Quartz (SiO2)
sedimentary