Chert (varieties: Flint or Jasper)
Silicon dioxide (SiO2) / Microcrystalline Quartz
sedimentary
Category
Man Made Material (Anthropogenic 'Mineraloid')
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Banded Chert (River Stone)
Silicon Dioxide (SiO2)
sedimentary
Chert / Flint
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Chert (Commonly known as Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (Jasper/Common Chert Pebble)
Microcrystalline Quartz (SiO2)
sedimentary
Ferrochrome Slag
Anthropogenic silicate/oxide glass (Complex silicate matrix with Cr-Fe-Si inclusions)
Industrial byproduct (often confused with igneous rocks or meteorites)
Diamond
Diamond (pure Carbon, C)
mineral
Coquina
Bioclastic Limestone
sedimentary
Polished/tumbled brown-and-white mineral fragment
Indeterminate; possibly quartz-rich jasper, brecciated jasper, or an iron-stained quartz mineral
mineral
Colorless faceted gemstone, likely quartz
Quartz (SiO₂), tentative identification; the photo is insufficient to confirm the material
gemstone
Obsidian
Volcanic Glass (predominantly SiO2, approximately 70% or more)
igneous
Granodiorite / Granite (Weathered)
Granodiorite
Igneous
Synthetic Marbled Aggregate (Footwear Component)
Ethylene-vinyl acetate (Croslite™)
not a rock (man-made polymer)
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Flint or chert fragment
Microcrystalline quartz (SiO₂), likely flint/chert
sedimentary
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Jasper)
Silicon Dioxide (SiO2)
sedimentary
Chert (Yellow/Tan variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert Nodule (Flint)
Chert (Silicon Dioxide, SiO2)
sedimentary
Diamond
Diamond (Pure Carbon, C)
mineral
Sandstone
Arenite
sedimentary
Coquina (Fossiliferous Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Green cabochon gemstone, likely aventurine or dyed chalcedony
Indeterminate from image; possible quartz variety (SiO₂), including aventurine quartz or chalcedony
gemstone
Polished blue chalcedony (possibly agate)
Microcrystalline quartz, SiO₂; chalcedony, potentially banded agate
mineral
Diamond
Diamond (pure Carbon, C)
mineral
Coquina
Bioclastic Limestone (Coquina)
sedimentary
Polished jasper pebble
Jasper, an opaque microcrystalline variety of quartz (SiO₂), with possible iron-oxide and other mineral inclusions
mineral
Blue glassy cabochon, likely blue quartz or synthetic glass
Possibly dyed blue chalcedony/quartz (SiO₂); visual identification is inconclusive
gemstone
Polished, carved gemstone (possibly dyed agate or glass-like material)
Unconfirmed from the image; no specific mineral can be identified reliably
gemstone
Green cabochon gemstone, likely nephrite jade
Nephrite jade—interlocking amphibole fibers, chiefly tremolite-actinolite, Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂
gemstone
Tumbled amethyst quartz
Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron impurities and irradiation
gemstone
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
igneous
Polished blue stone, likely sodalite or dyed agate
Sodalite: Na₈(Al₆Si₆O₂₄)Cl₂; exact identification requires testing
mineral
Tumbled brown chalcedony or jasper
Microcrystalline quartz, SiO₂; possibly iron-bearing jasper
mineral
Pearls
Aragonite (calcium carbonate) and Conchiolin
Mineraloid
Porcelain (Kaolin-based)
Alumina silicate ceramic (composed primarily of Kaolinite: Al2Si2O5(OH)4)
metamorphic (man-made/engineered)
Chert (Flint / Jasper)
Silicon Dioxide (SiO2)
sedimentary
Diamond (in Jewelry)
Carbon (C)
mineral
Jasper
Silicon dioxide (SiO2) with impurities
sedimentary
Sandstone
Arenite (SiO2, often with CaCO3 or Fe2O3 cement)
sedimentary
Polished rutilated quartz cabochon
Quartz (SiO₂) with rutile inclusions (TiO₂)
gemstone