Man Made Material

Chalcedony (Common Opal/Chert variety)

Silicon Dioxide (SiO2)

Diamond

Diamond (pure carbon; C)

Quartz (likely) / Siliceous rock with quartz phenocrysts (if a rock fragment)

Quartz (SiO₂)

Pyrite

Pyrite (Iron Disulfide), FeS2

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.

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Calcite

Calcite (Calcium Carbonate, CaCO3)

Fuchsite Quartzite

Fuchsite-bearing Quartzite

Petrified Wood

Silicified wood, primarily composed of Quartz (SiO2)

Granite

Granite (a plutonic igneous rock)

Quartz with Iron Stains

Quartz (SiO2) with iron oxide/hydroxide staining

Agate

Agate (a cryptocrystalline variety of Quartz, SiO₂)

Shale (possibly)

Shale (fine-grained clastic sedimentary rock)

Diamond

Diamond (pure carbon, C)

Quartz (in a rock matrix)

Quartz (SiO2)

Granite

Granite (a felsic intrusive igneous rock)

Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Basalt

Basalt (extrusive igneous rock)

Amazonite

KAlSi3O8 (Potassium Feldspar, variety of Microcline)

Sandstone

Arenite or Sandstone

Sugilite

Sugilite (KNa2(Fe,Mn,Al)2Li3Si12O30)

Carnelian

Chalcedony (cryptocrystalline quartz), SiO2

Marble

Marbles are primarily composed of calcite (calcium carbonate, CaCO3) or dolomite (calcium magnesium carbonate, CaMg(CO3)2).

Quartzite

Quartzite (primarily SiO2)

Chrysoprase

Chrysoprase (a variety of Chalcedony, SiO₂)

Quartz (likely a weathered/tumbled piece)

Quartz (SiO₂)

Himalayan Salt

Halite (mineral name), chemical formula NaCl (sodium chloride). Generally, 'Himalayan Salt' is a trade name for evaporite minerals from specific regions.

Chalk

Calcareous Ooze (composed primarily of coccoliths)

Quartz (pebble)

Quartz (SiO₂)

Halite

Halite (NaCl)

Quartz (milky quartz variety)

Quartz (SiO₂)

Garnet (likely Pyrope or Almandine)

Garnet Group (complex nesosilicate minerals, e.g., Pyrope Mg3Al2(SiO4)3, Almandine Fe3Al2(SiO4)3, Spessartine Mn3Al2(SiO4)3, Grossular Ca3Al2(SiO4)3, Andradite Ca3Fe2(SiO4)3, Uvarovite Ca3Cr2(SiO4)3). The vivid red color in the image strongly suggests Pyrope or Almandine.

Sandstone

Sandstone (Clastic Sedimentary Rock)

Sandstone (Pebble/Conglomerate fragment)

Sandstone (clastic sedimentary rock)

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)

Caliche (also known as hardpan, calcrete, kankar)

Primarily composed of calcium carbonate (CaCO₃), often mixed with other minerals like quartz, clay minerals, and iron oxides.

Quartz

Quartz (SiO₂ - Silicon Dioxide)

Quartz (Rock Crystal)

Quartz (SiO₂ - Silicon Dioxide)

Quartz

Silicon Dioxide (SiO₂)

Muscovite Mica

Muscovite (KAl₂(AlSi₃O₁₀)(F,OH)₂))