Chert (specifically Flint or Dark Chalcedony)
Silicon Dioxide (SiO2)
sedimentary
Category
Anthropogenic (Man Made Material Processed By Nature)
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Chert (Flint/Novaculite)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide staining/cementing)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Red Sandstone
Arenite (typically with iron oxide/hematite cement)
sedimentary
Quartz (Small fragments)
Silicon Dioxide (SiO2)
mineral
Chert (Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Amethyst (likely rough or cleaved fragment)
Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron impurities and irradiation
mineral
Rose Quartz with Schist Matrix
Silicon Dioxide (SiO2) with Mica-Schist
mineral
Sandstone (Quartzose)
Arenite (SiO2 principal)
sedimentary
Sandstone
Arenite (Siliclastic sedimentary rock)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Rough Diamond
Diamond (Native Carbon), C
mineral
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Chalcedony
Silicon Dioxide (SiO2)
mineral
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Diamond
Carbon (C)
gemstone
Chalcedony
Silicon Dioxide (SiO2)
mineral
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Quartz-rich breccia or altered granite fragment
Polymineralic quartz–feldspar rock, likely hydrothermally altered granite/pegmatite
igneous
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone
Arenite (primarily Quartz, SiO2)
sedimentary
Sandstone (Red Sandstone)
Clastic Sedimentary Rock (primarily SiO2 with Iron Oxide)
sedimentary
Sandstone (Beach Pebble)
Clastic sedimentary rock (primarily Quartz and Feldspar)
sedimentary
Likely purple quartzite or purple chert
Quartzite/chert, predominantly microcrystalline SiO₂; exact identification requires testing
metamorphic
Diamond
Diamond (pure carbon; C)
Mineral
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Red Sandstone (Old Red Sandstone)
Ferruginous Sandstone (SiO2 + Fe2O3)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Milky quartz cluster
Quartz (silicon dioxide, SiO₂), likely druzy or microcrystalline quartz
mineral
Bituminous Coal
Organic sedimentary rock (humic coal)
sedimentary
Red gemstone ring, likely garnet or synthetic ruby
Possibly almandine garnet (Fe₃Al₂(SiO₄)₃) or corundum/ruby (Al₂O₃); image alone cannot distinguish
gemstone
Sedimentary Sandstone with Iron Oxide
Ferruginous Sandstone
sedimentary
Diamond
Diamond (pure carbon, C)
Mineral
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
mineral
Sandstone Pebble
Arenite (primarily SiO2)
sedimentary
Rough Black Diamond (Bort / Carbonado)
Diamond (C)
mineral
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 staining)
sedimentary