Anthropogenic Material (Man Made Sedimentary Mimic)

Coal (Anthracite / Bituminous)

Organic Sedimentary Rock (Carbon-based)

Chert (Flint)

Chert (Cryptocrystalline Silica, SiO2)

Fossilized Coral (Coquina/Limestone)

Cnidaria Anthozoa (Fossilized)

Coquina

Bioclastic Limestone (composed primarily of CaCO3)

Chert (Flint Arrowhead)

Silicon Dioxide (SiO2)

Sandstone

Arenite

Chalk

Calcium carbonate (CaCO3)

Coquina

Biogenic Limestone (Coquina)

Carnelian cabochon pendant

Carnelian, orange-red chalcedony (microcrystalline quartz, SiO₂)

Chert (often called Flint)

Chert (SiO2)

Banded Agate

Cryptocrystalline Quartz (SiO2)

Chert (Beach Pebble)

Microcrystalline Quartz (SiO2)

Blue glass-like bead or gemstone keychain ornament

Indeterminate; likely cobalt-blue glass or synthetic blue spinel, not identifiable as a natural mineral from the image

Crushed Stone / Gravel

Aggregatus saxum (variable mineral composition)

Sandstone (Quartzose)

Sandstone (SiO2 dominated)

Turquoise-style beaded bracelet

Turquoise, hydrated copper–aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O; possibly dyed or composite beads

Chert (and associated river cobbles)

Silicon dioxide (SiO2)

Chert (and/or Flint)

Chert (Cryptocrystalline variety of Quartz, SiO2)

Limestone

Calcareous sedimentary rock (CaCO3)

Red Dyed Howlite

Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)

Sandstone (likely Quartzose Sandstone)

Arenite

Fossiliferous limestone

Bioclastic carbonate rock, chiefly calcite (CaCO₃)

Carnelian

Chalcedony (cryptocrystalline quartz), SiO2

Bituminous Coal (with Anthracite or Vitrinite inclusion)

Organic-rich Sedimentary Rock (Carboniferous classification)

Chert (often called Flint or Agate nodule)

Cryptocrystalline Quartz (SiO2)

Chert (and Jasper/Chalcedony mixture)

Microcrystalline Quartz (SiO2)

Red Sandstone

Quartz Arenite (iron-stained) / SiO2

Titanium Aura Quartz (Aura Quartz)

Titanium-coated Silicon Dioxide (SiO2)

Paving-concrete aggregate with a rounded stone

Polymictic gravel aggregate; the central clast appears to be weathered sandstone or volcanic rock

Liesegang Banded Sandstone (Concretion / Weathered Pebble)

Sandstone showing Liesegang rings / Weathering rind (SiO2 with iron oxides)

Chert (Arrowhead variety)

Chert (SiO2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Blue Goldstone

Synthetic Aventurescent Glass (Cobalt-doped soda-lime glass)

Likely flint (chert) fragment

Microcrystalline quartz (SiO₂), variety chert

Blue Goldstone

Aventurine Glass (SiO2 with Cobalt/Copper inclusions)

Slate

Metamorphic Pelitic Rock

N/A - Man-made object (Jewelry Chain)

Antiqued or Oxidized Metal Chain (often Steel or Brass)

Diamond

Native Carbon (C)

Chert (often called Flint)

Microcrystalline Quartz (SiO2)

Sandstone (Red/Brown Variety)

Arenite (composed primarily of SiO2 with Fe2O3 iron oxide inclusions)

Chert or silicified sedimentary fragment (tentative)

Microcrystalline quartz (SiO₂), possibly silicified limestone or fossil-bearing chert

Flint or chert, possibly a knapped stone tool

Microcrystalline quartz (SiO₂), commonly chalcedony with possible carbonaceous impurities