Organic Gemstone (Often Associated With Sedimentary Sequences)

Red Sandstone (Siltstone Pebble)

Arenite / Siltstone with Iron Oxide (Fe2O3)

Yellow Jasper

Opaque Cryptocrystalline Quartz (SiO2)

Limestone pebble

Sedimentary rock, primarily calcium carbonate (CaCO3)

Turquoise and Red Coral

CuAl6(PO4)4(OH)8·4H2O (Turquoise) and Corallium rubrum (Red Coral)

Jasper

Silicon Dioxide (SiO2) with impurities

Chert (Jasper/Flint variety)

Microcrystalline quartz (SiO2)

Chert (Yellow variety)

Microcrystalline quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Tumbled blue sodalite (probable)

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂

Chert (Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Mica Schist

Mica Schist (Muscovite subclass)

Fluorite

Calcium Fluoride (CaF2)

Unakite

Epidotized Granite

Chert (Common Opal/Jasper mix)

Silicon Dioxide (SiO2) with impurities

Amber

Succinite (fossilized resin, C10H16O)

Greywacke (River/Beach Pebble)

Greywacke (Impure Sandstone)

Que Sera Stone (Llanite with Feldspar and Quartz)

Rhyolite with blue quartz and pink orthoclase (Llanite-type quartz porphyry)

Blue Sapphire (Raw/Tumbled Corundum)

Corundum (Aluminum Oxide, Al2O3 with Fe/Ti traces)

Chert (Jasper)

Cryptocrystalline Quartz (SiO2)

Chert (Jasper variation)

Silicon Dioxide (SiO2)

Chrysocolla

Hydrated copper silicates (Cu,Al)2H2Si2O5(OH)4·nH2O

Manganese-coated Sandstone

Clastic sedimentary rock with Manganese Oxide (often Pyrolusite or Psilomelane)

Chrysocolla (with Hematite/Iron Oxides)

Chrysocolla: (Cu, Al)2H2Si2O5(OH)4 · nH2O

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (often called Flint or Jasper)

Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)

Pearl

Calcium Carbonate (Aragonite/Calcite) with Conchiolin

Jasper

Microcrystalline Quartz (SiO2)

Jasper

Microcrystalline Quartz (SiO2)

Chert (Concretion or Nodular Variety)

Microcrystalline Quartz (SiO2)

Chert (Flint Nodules)

Silicon Dioxide (SiO2)

Pyrite (Fool's Gold) in Matrix

Iron Disulfide (FeS2)

Jasper

Silicon dioxide (SiO2) with impurities

Orange Calcite

Calcium Carbonate (CaCO3)

Red Jasper

Silicon Dioxide (SiO2) with iron inclusions

Jasper

Silicon dioxide (SiO2)

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Green Onyx (Banded Calcite)

Travertine (CaCO3 - Calcium Carbonate)

River Jasper (Chert/Chalcedony mix)

Silicon Dioxide (SiO2) with iron oxide and chlorite inclusions

Chert (and associated river cobbles)

Silicon dioxide (SiO2)

Fossiliferous Limestone

Bioclastic Limestone (Calcium Carbonate, CaCO3)

Rhodonite

Rhodonite (Manganese Silicate), (Mn,Fe,Mg,Ca)SiO3

Pyrite (Fool's Gold) Cube

Iron Sulfide (FeS2)