Not A Rock Or Mineral (Anthropogenic Material)

Stiped Slate Beach Pebble

Low-grade Metamorphic Slate with Quartz Vein (SiO2 on Phyllosilicate base)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)

Chert

Microcrystalline Quartz (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Eudialyte in Matrix

Na15Ca6Fe3Zr3Si26O72(OH,Cl,H2O)3

Granite

Granite (Felsic Plutonic Rock)

Moss Agate and Druzy Quartz Carving

Cryptocrystalline Silica (SiO2) with impurities

Green Quartz (Prasiolite)

Silicon Dioxide (SiO2) with trace impurities

Agate

Silicon dioxide (SiO2)

Blue Lace Agate

Silicon dioxide (SiO2) - Chalcedony variety

Gold Nugget Jewelry

Native Gold (Au)

River Stone (likely Siltstone or fine-grained Sandstone)

Clastic Sedimentary Rock (Lithic Wacke / Siltstone)

Sandstone

Arenite (primarily SiO2)

Sandstone Pebble

Arenite (primarily SiO2)

Sandstone

Arenite (primarily SiO2)

Sandstone

Arenite (primarily SiO2)

Sandstone Pebbles

Arenite (Sedimentary rock composed of sand-sized grains)

Banded Calcite (Green Onyx)

Calcium Carbonate (CaCO3)

Sandstone (Ferruginous)

Arenite (Fe-rich)

Lapis Lazuli

Lapis Lazuli (Primary mineral: Lazurite (Na,Ca)8(AlSiO4)6(SO4,S,Cl)2)

Travertine (often colloquially called Tufa)

Chemical Sedimentary Calcium Carbonate (CaCO3)

Banded Gneiss (Variety of Gneiss)

Gneiss (specifically, a variety exhibiting prominent banding; mineral composition can vary, but often contains quartz, feldspar, mica, and amphibole)

Andesite

Andesite (Intermediate Extrusive Volcanic Rock)

Granite

Phaneritic Felsic Igneous Rock

Banded Agate (specifically Carnelian Agate color)

Silicon Dioxide (SiO2) - variety of Chalcedony

Granite

Granite (composed primarily of Quartz SiO2 and Feldspar (KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8))

Basalt

Extrusive mafic igneous rock

Granite

Phaneritic Igneous Rock (Granite)

Iron-stained Quartz

Silicon Dioxide (SiO2) with Hematite/Limonite impurities

Blue Chalcedony

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Serpentinite

Serpentinite (group of hydrous magnesium iron phyllosilicates)

Dalmation Stone

Peralkaline Rock (SiO2 with Arfvedsonite)

Ruby in Zoisite with Hornblende

Anyolite (Ruby: Al2O3, Zoisite: Ca2Al3(SiO4)3(OH))

Garnet Schist or Garnet-bearing Quartzite

Metamorphic rock containing Almandine Garnet (Fe3Al2(SiO4)3) and Quartz (SiO2)

Serpentinite

Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4

Almandine Garnet in Schist

Almandine Garnet (Fe3Al2(SiO4)3) in Mica Schist

Granite

Granite (a common term for a felsic intrusive igneous rock)

Basalt with Quartz Veins

Basalt (SiO2 range 45-52%)

Rose Quartz

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