Organic Gemstone (Not A Rock Or Mineral In The Traditional Sense, But Bio Mineralized Material)

Blue Sapphire

Corundum (Al2O3)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartz (Clear / Rock Crystal)

Silicon Dioxide (SiO2)

Rough Dark Green Sapphire

Corundum (Al2O3)

Smoky Quartz on Matrix

Silicon Dioxide (SiO2) with trace impurities and aluminum inclusions

Quartz

Quartz (SiO₂ - Silicon Dioxide)

Blue Quartzite

Quartzite (primarily SiO2 with inclusions like Dumortierite or Magnesio-riebeckite)

Quartz (specifically Clear Quartz or Rock Crystal)

Silicon Dioxide (SiO2)

Dalmatian Jasper (or Dalmatian Stone)

Dalmatian Stone (A peralkaline felsite composed of feldspar, quartz, and sodic amphibole)

Chalcedony Geode

Chalcedony (SiO2) within a geode structure

Yellow Quartz (Citrine Quartz or Yellow Jasper)

Silicon Dioxide (SiO2) with iron impurities

Asphalt (Bituminous Concrete)

Composite material (bitumen binder with mineral aggregate)

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Almandine Garnet

Iron aluminum silicate (Fe3Al2(SiO4)3)

Red Jasper

Silicon dioxide (SiO2) with iron oxide inclusions

Lepidolite

K(Li,Al)3(Si,Al)4O10(F,OH)2

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Granite

Granite (a plutonic igneous rock composed of quartz, feldspar, and mica)

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

Pink Sapphire

Corundum (Al2O3 with trace Chromium and Iron)

Basalt

Basalt

Red Garnet

Garnet Group (e.g., Pyrope, Almandine, Spessartine, Grossular, Andradite, Uvarovite)

Ruby in Zoisite

Ruby (Corundum, Al2O3) in Zoisite (Calcium aluminum silicate hydroxide, Ca2Al3(SiO4)3(OH)) with some Hornblende

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Grey Slate

Foliated Metamorphic Rock (formed by low-grade regional metamorphism of shale or mudstone)

Epidote

Epidote (Ca2(Al,Fe)3(SiO4)3(OH))

Biotite Mica

K(Mg,Fe2+)3(Al,Fe3+)Si3O10(OH,F)2

Sapphire (likely blue synthetic sapphire or blue glass in a ring)

Corundum (Al₂O₃), specifically the blue variety due to trace amounts of iron and titanium impurities. If synthetic, it would still be Al₂O₃.

Green Agate

Silicon dioxide (SiO₂)

Jasper (specifically Red Jasper or Iron-stained Chert)

Silicon dioxide (SiO2) with iron oxide inclusions

Mica Schist

Mica Schist (primarily Muscovite and Quartz)

Rutilated Quartz

SiO2 with TiO2 inclusions

Carnelian

Carnelian (a variety of Chalcedony, SiO₂)

Diamond

Diamond (C)

Granite (Pink/Red variety)

Phaneritic Felsic Intrusive Igneous Rock (composed primarily of Quartz, K-Feldspar, and Plagioclase)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Corundum (Sapphire in Host Rock)

Corundum (Aluminum Oxide, Al2O3)

Turquoise

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

Chert (Nodule)

Silicon dioxide (SiO2) - Cryptocrystalline Quartz

Diamond

Diamond (C)