Limestone

Chert (Nodule)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (specifically Flint)

Silicon dioxide (SiO2)

Galena

Lead(II) sulfide (PbS)

Cryptocrystalline Quartz (Agate/Chert)

Silicon dioxide (SiO2)

Green Fluorite

Calcium Fluoride (CaF2)

Green Fluorite

Fluorite (Calcium Fluoride, CaF2)

Green Jade (specifically Nephrite)

Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)

Fluorite (Purple Octahedron)

Calcium Fluoride (CaF2)

Bay Scallop Shell

Argopecten irradians (Biogenic Calcium Carbonate / CaCO3)

Orange Calcite

Calcite (Calcium Carbonate, CaCO3)

Lapis Lazuli

Complex metamorphic rock primarily composed of Lazurite ((Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2), Calcite, and Pyrite

Chert (varietal: Flint Pitted Pebble)

Cryptocrystalline Quartz (SiO2)

Chert (specifically Red Chert / Jasper)

Silicon Dioxide (SiO2)

Orange Calcite

Calcium Carbonate (CaCO3)

Fluorite

Calcium Fluoride (CaF2)

Epidote Water-Worn Pebble

Epidote {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)

Sandstone Geode (Unbroken)

Siliciclastic sedimentary rock (primarily Quartz)

Chert Pebble (Yellow/Brown Jasper variety)

Microcrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Tiffany Stone

Bertrandite Fluorite (CaF2 + Be4Si2O7(OH)2)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Green Fluorite

Fluorite (Calcium Fluoride - CaF2)

Blue Calcite

Calcium Carbonate (CaCO3)

Tree Agate (also known as Dendritic Agate)

Silicon Dioxide with inclusions (SiO2 + Mn/Fe)

Green Calcite

Calcium Carbonate (CaCO3)

Travertine (Calcareous Tufa)

Calcium Carbonate (CaCO3)

Orange Calcite

Calcium Carbonate (CaCO3)

Yellow Calcite

Calcium Carbonate (CaCO3)

Chert (and/or River Pebble)

Microcrystalline silica (SiO2)

Chert Nodule (Commonly known as a Flint or River Cobble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Marble

Recrystallized Calcite (CaCO3)

White Marble

Recrystallized Calcite (CaCO3)

Fossiliferous Limestone (Crinoidal)

Calcium Carbonate (CaCO3) - Limestone containing bioclasts

White Marble (Industrial/Architectural)

Recrystallized Calcite (CaCO3)

Chert (specifically Flint or Dark Chalcedony)

Silicon Dioxide (SiO2)

Chert (with Quartz vein)

Chert (Silicon Dioxide, SiO2)

Chert Pebble with Quartz Veining

Microcrystalline Quartz (SiO2)

Orange Calcite

Calcium Carbonate (CaCO3)

Granite

Granite (composed primarily of Quartz SiO2, Alkali Feldspar KAlSi3O8, and Plagioclase Feldspar)

Chert (specifically Gray/Blue Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Banded Calcite (often sold as 'Ocean Jasper' or 'Caribbean Calcite' variant)

Calcium Carbonate (CaCO3) with potential Aragonite inclusions

Chert / Flint

Microcrystalline or cryptocrystalline quartz (SiO2)