Anthropogenic (Man Made Artifact)

Chert / Flint

Cryptocrystalline Quartz (SiO2)

Jasper (Red Jasper with Quartz veins)

Jasper (Silicon Dioxide, SiO2)

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Shale

Fissile mudrock (composed of clay-sized particles and detrital grains)

Sandstone

Arenite (primarily Quartz, SiO2)

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Diabase (also known as Dolerite)

Diabase / Microgabbro

Green Fluorite

Calcium Fluoride (CaF2)

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with impurities)

Amber

Succinite (Fossilized Tree Resin)

Emerald

Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities

Quartz (Clear / Rock Crystal)

Silicon Dioxide (SiO2)

Serpentine

Serpentinite (a rock composed primarily of serpentine minerals like antigorite, chrysotile, and lizardite; general formula (Mg, Fe)3Si2O5(OH)4)

Hypersthene (or Enstatite/Ferrosilite)

Orthopyroxene series (Mg,Fe)SiO3 - specifically, historically hypersthene (intermediate member) now referred to as Enstatite (Mg-rich) or Ferrosilite (Fe-rich)

Milky Quartz

Silicon Dioxide (SiO2)

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Serpentinite

Serpentinite ((Mg,Fe,Ni,Al)3Si2O5(OH)4)

Peridotite (Olivine/Peridot)

Peridotite: (Mg,Fe)2SiO4 (Olivine-rich ultramafic rock)

Pink Granite

Phaneritic Felsic Intrusive Igneous Rock

Prehnite

Prehnite (Ca2Al2Si3O10(OH)2)

Quartzite

Quartzite (primarily SiO2)

Banded Iron Formation (BIF) / Tiger Iron

Ferruginous Chert (primarily Quartz [SiO2] and Hematite/Magnetite [Fe2O3/Fe3O4])

Red Quartzite Cobble

Quartzite (primarily SiO2)

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Hematite (Iron Ore)

Hematite (Fe2O3)

Granite with Epidote

Granite, containing quartz, feldspar, and epidote

Agate Nodule / Weathered Chert

SiO2 (Silicon Dioxide - Microcrystalline Quartz)

Fluorite (translucent octahedral crystal)

Calcium fluoride (CaF2)

Native Copper

Native Copper (Cu)

Carnelian Agate

Silicon Dioxide (SiO2) with Hematite inclusions

Quartz Pebble

Silicon Dioxide (SiO2)

Quartzite

Quartzite (primarily Silicon Dioxide, SiO2)

Red Jasper (possibly Wonderstone)

Silicon Dioxide (SiO2) with iron oxide inclusions

Amethyst

Amethyst (Silicon Dioxide - SiO2 with iron impurities)

Carnelian (a variety of Chalcedony)

SiO2 (Silicon Dioxide) - Cryptocrystalline Quartz

Fluorite

Calcium Fluoride (CaF2)

Gold Nugget

Native Gold (Au)

Quartzite

Quartzite (SiO2)

Green Aventurine

Aventurine Quartz (SiO2 with Fuchsite inclusions)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Red Sandstone

Arenite (primarily Quartz, SiO2, with Iron Oxide cementing agent)