Anthropogenic (Man Made Product Subject To Geological Processes)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Mineral

Basalt (Road Aggregate)

Basalt (Aphanitic Mafic Igneous Rock)

igneous

Red Sandstone

Arenite (primarily composed of SiO2 with Fe2O3 cement)

Obsidian

Obsidian (Volcanic Glass), primarily SiO2 (70% or more silicon dioxide)

Igneous

Dendritic Agate or Spotted Quartzite

Silicon Dioxide (SiO2) with inclusions

Petrified Wood

Silicified Wood (primarily Silicon Dioxide, SiO2)

Sandstone

Arenite (primarily SiO2)

Milky Quartz (Ferruginous variety)

Silicon Dioxide (SiO2)

Selenite (Satin Spar)

Gypsum (CaSO4·2H2O)

Mineral, often a rock given its aggregate nature

Yellow Jade (often Serpentine or Dolomite)

Primarily Serpentine (Mg3Si2O5(OH)4) or Dolomite (CaMg(CO3)2), though the term 'yellow jade' is also sometimes applied to varieties of true nephrite or jadeite.

Pyrite

Iron Disulfide (FeS2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Amygdaloidal Basalt

Basalt with secondary mineral infilling

igneous

Sandstone

Arenite (primarily SiO2 - Silicon Dioxide)

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with impurities)

Igneous

Quartz

Silicon Dioxide (SiO2)

Quartz

Quartz (Silicon Dioxide, SiO2)

Quartz

Silicon Dioxide (SiO₂)

Mineral

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Clear/White Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Yellow Calcite

Calcite (Calcium Carbonate, CaCO3)

Synthetic (Man-made material mimicking natural stone)

Glazed Ceramic Tile

Fused Silicate-Clay composite

Clear Quartz

Silicon Dioxide (SiO2)

Quartz (specifically Milky/Yellow Quartz)

Silicon Dioxide (SiO2)

Quartzite (or Milky Quartz pebble)

Quartzite (Metamorphosed Sandstone) / Silicon Dioxide (SiO2)

Quartzite

Quartzite (SiO2)

Black Tourmaline (Schorl)

Sodium Iron Aluminum Borate Silicate (NaFe3Al6(BO3)3Si6O18(OH)4)

Quartz

Silicon Dioxide (SiO2)

Sandstone (Quartz Arenite)

Sandstone (Chemical formula: primarily SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

Sandstone

Arenite (SiO2 based)

Milky Quartz

Silicon Dioxide (SiO2)

Quartzite

Quartzite (primarily SiO2)

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

Yellow Calcite

Calcite (Calcium Carbonate, CaCO3)

Petrified Wood

Silicified wood (Quartz variant, SiO2)

Biotite Mica

K(Mg, Fe)3AlSi3O10(F, OH)2

Quartz (Clear/White)

Silicon Dioxide (SiO2)