Man Made Material (Anthro Lithic Product)

Grooved Maun Ball (Maul/Hammerstone-like Concretion)

Calcareous/Ferruginous Concretion in Sandstone Matrix

Moonstone (in a halo ring setting)

Orthoclase Feldspar (containing alternating layers of Albite), (KAlSi3O8)

Chert / Jasper and River Stones

Microcrystalline Quartz (SiO2)

Pearl

Organic gemstone (Calcium carbonate - CaCO3)

Pyrite

Iron Disulfide (FeS2)

Quartz

Silicon Dioxide (SiO₂)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Banded Gneiss

Gneiss (typically quartz, feldspar, mica, amphibole composition)

Sandstone

Arenite

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Quartz

Silicon Dioxide (SiO2)

Chert (Flint)

Chert (SiO2)

Chert (Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (Flint variety)

Silicon Dioxide (SiO2)

Pearl

Aragonite / Calcium Carbonate (CaCO3)

Quartz (likely milky quartz or a stained variety)

Silicon Dioxide (SiO₂)

Bauxite

Bauxite (Al(OH)3, γ-AlO(OH), and α-AlO(OH))

Pyrite

Iron Sulfide (FeS2)

Chert (often referred to as 'Jasper' when red)

Chert (microcrystalline quartz, SiO₂)

Obsidian

Volcanic Glass (SiO2 - Silicon Dioxide with impurities)

Granite

Granite (a felsic intrusive igneous rock)

Chert (Tan/Grey variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (often called Flint when dark)

Microcrystalline silicon dioxide (SiO2)

Chert (Flint)

Chert (SiO2)

Chert (often called Flint)

Microcrystalline Quartz (SiO2)

Granite

Granite (Felsic intrusive igneous rock)

Chalk

Calcium Carbonate (CaCO3)

Pyrulite (Pyrite / Chalcopyrite)

Iron Sulfide (FeS2) or Copper Iron Sulfide (CuFeS2)

Pebble (likely a type of sandstone or quartzite pebble)

Clastic Sediment (specifically, a rudite-sized clast). If the pebble is composed of a specific rock type, its scientific name would be that rock type (e.g., 'Quartzite pebble', 'Granite pebble', 'Chert pebble'). Given its appearance, it is likely a metamorphic quartzite pebble or a hard sandstone pebble.

Diamond

Diamond (pure Carbon, C)

Amethyst Geode/Cluster

Quartz (SiO2) - variety Amethyst

Chert (Flint variety)

Microcrystalline Quartz (SiO2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Diamond

Diamond (pure carbon C)

Cobalt Blue Sea Glass

Amorphous Silica Glass (SiO2 + CoO)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Citrine Quartz

Silicon Dioxide (SiO2) with iron impurities

Flint (Chert)

Silicon Dioxide (SiO2)

Petrified Wood (Agatized/Silicified Wood)

Silicified Wood (SiO2 - Silicon Dioxide)

Slate

Foliated Metamorphic Rock (primarily composed of quartz, illite, and chlorite)

Smoky Quartz Cluster

Smoky Quartz (Silicon Dioxide - SiO2)

Chert (Flint)

Chert (Silicon Dioxide, SiO2)