Man Made Object (Ring)

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Sandstone (with potential Arkose/Lithic characteristics)

Arenite (Sedimentary rock composed of sand-sized grains)

Pink Granite

Phaneritic Felsic Igneous Rock (composed of orthoclase, quartz, and plagioclase)

Coquina

Biogenic Limestone (Calcite, CaCO3)

Coquina

Biogenic Limestone (Coquina)

Sandstone

Arenite (SiO2, often with CaCO3 or Fe2O3 cement)

Chert

Chert (SiO2)

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Obsidian

Volcanic Glass (70-75% SiO2 with MgO and Fe3O4)

Corundum (Sapphire variant)

Aluminium oxide (Al2O3)

Red Sandstone

Arenite (Ferruginous Sandstone)

Carnelian

Carnelian (Silicon Dioxide - SiO2 with Hematite impurities)

Carnelian

Carnelian (Silicon Dioxide, SiO2)

Lapis Lazuli

Lazurite-rich metamorphic rock; (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2

Amber

Succinite (organic mineraloid); Chemical formula: C10H16O

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Jasper

Jasper (Silicon Dioxide, SiO2)

Banded Agate (specifically Carnelian Agate)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Lapis Lazuli

Na8(Al6Si6O24)S2 (composed primarily of Lazurite, Calcite, and Pyrite)

Dalmatian Stone (often misnamed Dalmatian Jasper)

Aplite (with hornblende/arfvedsonite inclusions)

Sodalite

Sodalite (Na8(Al6Si6O24)Cl2)

Granite

Phaneritic Igneous Rock (composed mostly of Quartz, Feldspar, and Mica)

Granite

Granite (a phaneritic intrusive igneous rock)

Granite

Phaneritic Felsic Igneous Rock

Red Jasper

Silicon Dioxide (SiO2) with Hematite impurities

Charoite

Charoite (Hydrated potassium sodium calcium barium strontium silicate hydroxyfluoride)

Fossilized Gastropod (Snail)

Class Gastropoda (internal mold or 'steinkern')

Blue Chalcedony

Chalcedony (a cryptocrystalline variety of Quartz - SiO₂)

Nephrite Jade

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

Snowflake Obsidian

Volcanic glass with Cristobalite inclusions (70–75% SiO2)

Granite

Granite (Silicic Intrusive Igneous Rock)

Granite

Granite (phaneritic intrusive igneous rock consisting of quartz, feldspar, and mica)

Granodiorite

Granodiorite (Quartz + Plagioclase + Alkali Feldspar + Biotite/Hornblende)

Jasper (Iron-rich Chalcedony)

Jasper (Microcrystalline Silicon Dioxide, SiO2 plus iron oxide impurities)

Chert (Flint)

Silicon Dioxide (SiO2)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Chert (Yellow/Tan variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Blue Chalcedony

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Bivalve Fossil (Shell Fragment)

Class Bivalvia (Calcium Carbonate - CaCO3)

Amethyst

Amethyst (Silicon Dioxide - SiO2 with Iron impurities)

Banded Chert

Microcrystalline Quartz (SiO2)

Rhodonite

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