Synthetic (Not A Rock Or Mineral)

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Sandstone (Green/Yellow Siltstone variant)

Arenite or Siltstone (primarily SiO2 with mineral staining)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz (Milky/Granular)

Silicon Dioxide (SiO2)

Prehnite

Prehnite Ca2Al2Si3O10(OH)2

Rose Quartz

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

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Drupa Quartz (Sparkly Drusy Quartz on Matrix)

Crystalline Silicon Dioxide (SiO2) on host rock

Clear Quartz

Silicon Dioxide (SiO2)

Milky Quartz/Clear Quartz Cluster

Silicon Dioxide (SiO2)

Turquoise

Hydrated phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O

Sandstone (Quartzite Pebble)

Arenite (primarily SiO2)

Fire Opal (in matrix)

Hydrated Silica (SiO2·nH2O)

Prehnite

Ca2Al(AlSi3O10)(OH)2 (Calcium Aluminum Silicate hydroxide)

Jasper with Quartz inclusions

Silicon Dioxide (SiO2)

Milky Quartz with Mineral Inclusions

Silicon Dioxide (SiO2) with miscellaneous inclusions

Quartz (Chert/Chalcedony variety)

Silicon Dioxide (SiO2)

Red Sandstone

Arenite (primarily Quartz SiO2 with Hematite Fe2O3 cement)

Sandstone

Arenite (primarily SiO2 with various cementing agents)

Quartz

Silicon Dioxide (SiO2)

Moss Agate

Chalcedony (Silicon Dioxide) with dendritic inclusions (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

Sandstone (lithic/greywacke variety)

Arenite (composed primarily of SiO2 with various lithic fragments)

Red Sandstone

Arenite (Fe2O3-rich)

Granitic Quartz with Feldspar

Granite (composed primarily of SiO2 and KAlSi3O8)

Granite (including Pegmatite variants)

Phaneritic Plutonic Rock (composed primarily of Quartz SiO2, Feldspar KAlSi3O8, and Biotite/Muscovite mica)

Vesicular Basalt with Amygdules

Amygdaloidal Basalt

Chert with Quartz Veining

Silicon Dioxide (SiO2)

Banded Metamorphic Rock (likely Quartzite or Serpentinite/Soapstone)

Metamorphic Rock (possibly a banded Quartzite or a foliated Serpentinite/Talc Schist based on appearance, general term for such a rock is 'Banded Metamorphic Rock' or 'Gneiss' if pronounced banding of different minerals)

Turquoise (Green variety)

Hydrous phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O

Sandstone (likely Quartzose)

Arenite (SiO2 principal mineral)

Milky Quartz

Silicon Dioxide (SiO2)

Gneiss (High-Grade Metamorphic Rock)

Gneiss (primarily composed of Quartz, Feldspar, and Mica/Amphiboles)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Quartz (specifically Milky/Gray Quartz)

Silicon Dioxide (SiO2)

Sandstone (Quartzose)

Arenite (Siliciclastic sedimentary rock)

Quartz Veinated Sandstone or Siltstone

Silicon Dioxide (SiO2) within a clastic sedimentary matrix

Basalt with Plagioclase Microphenocrysts

Amygdaloidal or Porphyritic Basalt

Dalmation Stone (often called Dalmatian Jasper)

Peralkaline Rock (Microgranite/Aplite), SiO2 with inclusions of Arfvedsonite

Quartz Pebble

Silicon Dioxide (SiO2)

Sandstone

Arenite (composed primarily of SiO2)