Mineral (Tectosilicate)

Ocean Jasper (Orbicular Jasper)

Silica (SiO2) with varied mineral inclusions

Picture Jasper

Silicon Dioxide (SiO2) with mineral inclusions

Sandstone (likely Siltstone variety)

Arenite / Siltstone (primary mineral SiO2)

Chert (Serpentinized)

Silicon Dioxide (SiO2) with mineral staining

Quartz with Muscovite Mica

Silicon Dioxide (SiO2) with Potassium aluminum silicate hydroxide fluoride [KAl2(AlSi3O10)(F,OH)2]

Strawberry Quartz

Quartz (SiO2) with inclusions of Goethite or Hematite

Granite (Phaneritic Igneous Rock)

Granite

Blue Quartzite (Aventurine)

Silicon Dioxide (SiO2) with mineral inclusions

Gabbro

Basaltic Plutonic Rock (Gabbro)

Auriferous Quartz (Gold-bearing Quartz)

Silicon Dioxide (SiO2) with trace Gold (Au) and Iron Oxides

Prehnite

Prehnite - Ca2Al(AlSi3O10)(OH)2

Silver (Native Element)

Ag (Argentum)

Amygdaloidal Basalt with Epidote

Vesicular Basalt with secondary Epidote/Quartz mineral infill

Bauxite

Alumina ore (Mixture of Gibbsite, Boehmite, and Diaspore)

Limonite

Hydrous Iron Oxide (often Goethite FeO(OH), Lepidocrocite γ-FeO(OH), and other amorphous iron oxyhydroxides)

Amygdaloidal Basalt

Amygdaloidal Basalt

Sandstone (Calcareous or Ferruginous)

Clastic sedimentary rock (SiO2 with CaCO3 or Fe2O3 cement)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Quartz (Druzy)

Silicon Dioxide (SiO2)

Magnetite (in matrix)

Magnetite (Fe3O4)

Brecciated Chert

Sedimentary Chert (SiO2) with Calc-Silicate mineralization

Jasper (var. Ocean or Polychrome Jasper)

Silicon Dioxide (SiO2) with iron and mineral inclusions

Vesicular Basalt with Amygdaloidal Infill

Basalt (Mafic Extrusive Igneous Rock)

Granite

Granite (Felsic Plutonic Rock)

Banded Gneiss

Gneiss (High-grade Metamorphic Rock)

Azurite-Malachite (often a mixed specimen)

Azurite: Cu3(CO3)2(OH)2; Malachite: Cu2(CO3)(OH)2. The specimen appears to be a natural mixture or intergrowth of these two minerals.

Gneiss

Gneissic Metamorphic Rock

Olivine (Peridotite)

Magnesium iron silicate (Mg, Fe)2SiO4

Gneiss

Gneiss (High-grade Regional Metamorphism)

Magnetite / Ironstone Pebble

Magnetite (Fe3O4)

Chrysocolla

Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O)

Rose Quartz

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

Granite

Granite (Mainly Quartz, Alkali Feldspar, and Plagioclase)

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

Gneiss (Pebble)

Gneiss

Granite

Granite (Felsic intrusive igneous rock)

Serpentinite

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

Granite

Granite (Phaneritic Igneous Rock)

Granite

Phaneritic Felsic Igneous Rock

Granite

Granite (Felsic Plutonic Rock)

Gneiss

Gneiss (High-grade metamorphic rock)

Granite

Phaneritic Igneous Rock (Granite)