Chert (often colloquially called Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Category
Sedimentary (Biogenic)
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Clear Quartz
Silicon Dioxide (SiO2)
mineral
Mixed Gemstone and Mineral Collection
Mixed Silica and Carbonate minerals (SiO2, CaSO4·2H2O, etc.)
mineral
Yellow Chalcedony (Agate)
Silicon Dioxide (SiO2)
mineral
Yellow Calcite
Calcium Carbonate (CaCO3)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Psilomelane (Black Hematite varietal)
Barium Manganese Oxide (Ba,H2O)2Mn5O10
mineral
Jasper
Silicon Dioxide (SiO2)
mineral
Jasper
Silicon dioxide (SiO2)
sedimentary
Chalcedony
Chalcedony (SiO2)
mineral
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
mineral
Chert (Nodule)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Blue Chalcedony
Silicon Dioxide (SiO2)
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Quartz Geode
Quartz (Silicon Dioxide, SiO2) in a Geode
sedimentary
Magnetic Sand Grain / Magnetite Pellet
Magnetite (Fe3O4)
mineral
Blue Celestite (Celestine)
Strontium sulfate (SrSO4)
mineral
Clear Quartz Crystal
Silicon Dioxide (SiO2)
mineral
Turquoise
Turquoise, CuAl6(PO4)4(OH)8·4H2O
mineral
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Quartz Crystal Fragment
Silicon Dioxide (SiO2)
mineral
Satin Spar (often sold as Selenite)
Gypsum (CaSO4·2H2O)
mineral
Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Garnet (specifically Almandine)
Almandine - Fe3Al2(SiO4)3
metamorphic
Note: Image shows a biological specimen (Rat), not a rock. Representative geological equivalent: Galena (due to lead-grey colors in fur).
Galena (PbS)
mineral
Satin Spar (Gypsum)
Hydrous Calcium Sulfate (CaSO4·2H2O)
mineral
Satin Spar (Satin Spar Selenite)
Gypsum (CaSO4·2H2O)
mineral
Quartz (Granular)
Silicon Dioxide (SiO2)
mineral
Chert Nodule
Microcrystalline Quartz (SiO2)
sedimentary
Quartzite and Sandstone Pebbles
Silicon dioxide (SiO2)
metamorphic and sedimentary
Sandstone (with Iron Staining)
Clastic sedimentary rock (High Silica / Iron Oxide)
sedimentary
Limestone
Sedimentary Limestone (Calcium Carbonate, CaCO3)
sedimentary
Sandstone (Quartz Arenite)
Clastic Sedimentary Rock - Quartz Arenite
sedimentary
Sandstone (likely Quartzose type)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Sandstone (Graywacke type)
Clastic Sedimentary Rock (Lithic Sandstone)
sedimentary
Sandstone (specifically Arkose or Siltstone variant)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily Quartz, SiO2)
sedimentary
Sandstone (Micaceous)
Clastic Sedimentary Rock (primarily SiO2 with Mica)
sedimentary
Chert (Chalcedony/Flint)
Silicon Dioxide (SiO2)
sedimentary
Shale or Mudstone (Based on appearance)
Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)
Sedimentary
Bituminous Coal
Bituminous coal (Carbonaceous sedimentary rock)
sedimentary