Anthropogenic (Man Made Artifact)

Brecciated Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Rutilated Quartz (or Tourmalinated Quartz if inclusions are Tourmaline)

Silicon Dioxide (SiO2) with Rutile (TiO2) or Tourmaline inclusions

N/A (Non-Geological Object)

Carnelian

Carnelian (a variety of Chalcedony, SiO2)

Smoky Quartz

SiO2 (Silicon Dioxide)

Chert (Commonly known as Flint or River Pebble)

Microcrystalline Quartz (SiO2)

Jasper (specifically Red Jasper)

Silicon Dioxide with Iron Oxides (SiO2 + Fe2O3)

Agate (specifically Moss or Plume Agate nodding toward Agatized Wood)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz (Chalcedony)

Magnetite with Pyrite or Chalcopyrite inclusions

Magnetite (Fe3O4) with Pyrite (FeS2)

Agate Geode

Chalcedony (SiO2 - Silicon Dioxide)

Druzy Agate (specifically Black Druzy Agate)

Silicon Dioxide (SiO2)

Banded Agate (River Stone)

Agate (Silicon Dioxide - SiO2)

Banded Chert

Chert (a microcrystalline variety of quartz, SiO2 with minor impurities)

Greenschist

Greenschist (Chlorite-actinolite schist)

Red Sandstone (Iron-rich)

Ferruginous Sandstone (variable formula, primarily SiO2 + Fe2O3)

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

Sandstone

Arenite (primarily SiO2)

Standing Liberty Quarter (Silver Specimen)

Native Silver alloy (Ag with Cu traces)

Basalt

Extrusive mafic igneous rock

Peridot and Citrine Gemstones (in a ring setting)

Peridot (Olivine: (Mg,Fe)2SiO4), Citrine (Quartz: SiO2)

Quartzite

Quartzite (primarily SiO2)

Banded Gneiss (River Cobble)

Gneiss (a high-grade metamorphic rock)

Schist

Mica Schist

Amethyst

SiO2 (Silicon Dioxide) - Purple variety of Crystalline Quartz

Magnetic Hematite

Magnetized Hematite (an iron oxide mineral, Fe2O3, that has undergone magnetization)

Scoria (Volcanic Rock)

Scoria (often basaltic scoria)

Pink Quartzite

Quartzite (SiO2 with iron oxide inclusions)

Citrine Quartz

Silicon Dioxide (SiO2) with ferric iron impurities

Sandstone (Quartzite-rich Cobble)

Clastic sedimentary rock (primarily SiO2)

Turquoise (Blue Howlite / Magnesite imitation)

CuAl6(PO4)4(OH)8·4H2O (for natural Turquoise); Ca2B5SiO9(OH)5 (for Howlite)

Tektite (Indochinite)

Tektite (High-silica natural glass)

Limestone (Porous/Travertine variant)

Sedimentary Calcium Carbonate (CaCO3)

Chert (variant Flint/Jasper)

Microcrystalline Opaline Silica (SiO2)

Blue Lace Agate

Cryptocrystalline Quartz (SiO2) with trace minerals

Basalt (Vesicular/Amygdaloidal or Water-Worn)

Basalt

Oyster Shell (Aragonite/Calcite)

Calcium Carbonate (CaCO3)

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Granite

Granite (Phaneritic intrusive igneous rock; primarily SiO2 and Al2O3)

Gneiss

Gneiss (High-grade metamorphic rock typically composed of Quartz, Feldspar, and Mica/Amphibole)

Gneiss (specifically Granitic Gneiss)

Gneiss (composed primarily of Quartz, Feldspar, and Biotite/Amphibole)

Chalcedony

Chalcedony (SiO₂)

Quartz

Quartz (Silicon Dioxide - SiO2)