Organic Gemstone (Fossilized Resin)

Chert (Septarian or Nodular variety)

Microcrystalline Quartz (SiO2)

Chert (Common Opal/Jasper variety)

Microcrystalline Quartz (SiO2) with hydration

Limestone

Calcium Carbonate (CaCO3)

Crushed Limestone

Calcite-rich Sedimentary Rock (CaCO3)

Orange Calcite

Calcium Carbonate (CaCO3)

River Stone (likely Mudstone or Siltstone)

Lutite (Clastic sedimentary rock composed of clay and silt-sized particles)

Green Calcite

Calcium Carbonate (CaCO3)

Turquoise

Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)

Peridot

Olivine (Mg, Fe)2SiO4

Petrified Wood

Silicified wood (Quartz/Chalcedony replacement of organic matter)

Shale with Plant Fossils / Carbonaceous Shale

Laminated Mudrock (Siliciclastic)

Moss Agate

Silicon Dioxide with inclusions (SiO2 + impurities)

Chert (variant Flint/Jasper)

Microcrystalline Opaline Silica (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Emerald (Faceted Gemstone)

Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Jadeite and Assorted Corundum (Ruby/Sapphire) / Beryl (Emerald)

Jadeite (NaAlSi2O6), Ruby/Sapphire (Al2O3), Emerald (Be3Al2(SiO3)6)

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood

Silicified Wood (primarily SiO2)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically Jasper/Flint pebble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Chert (and/or Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (Jasper/Flint variant)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (varietal: Jasper or Flint)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Petrified Wood

Silicified Wood (SiO2)

Septarian Nodule (Dragon Stone)

Septarian concretion (composition: CaCO3 - Calcite, Aragonite, and Siderite/Limestone)

Fossiliferous Rock (likely Dinosaur Fossil in Matrix)

Permineralized Vertebrate Fossil (Calcium Carbonate/Silica replaced bone material)

Chert (River Pebble)

Microcrystalline quartz (SiO2)

Chert (specifically Chert Nodule/Flint)

Chert (Silicon Dioxide, SiO2)

Limestone (Concretionary or Tufa)

Calcium Carbonate (CaCO3)

Chert (specifically Yellow/Brown Chert or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Red Jasper variant)

Microcrystalline Quartz (SiO2)

Sandstone

Arenite (primarily composed of SiO2)

Chert (variant Flint)

Silicon Dioxide (SiO2)

Chert (Nodule)

Microcrystalline or Cryptocrystalline Silica (SiO2)

Quartz Geode in Chert/Limestone Matrix

Silicon Dioxide (SiO2) within Sedimentary Host Rock

Picture Jasper

Silicon Dioxide (SiO2) - Opaque Chert/Quartzite variety

Chert (Flint variety)

Chert (Microcrystalline or Cryptocrystalline Quartz), SiO2

Banded Chert

Microcrystalline silicon dioxide (SiO2)

Chert / River Pebble

Microcrystalline Silica (SiO2)

Shale

Shale (fine-grained clastic sedimentary rock)