Rutilated Quartz

Hardness: 7 on the Mohs scale. Color: Typically white, clear, or smoky, but the inclusions give it a silvery, golden, or dark metallic appearance. Luster: Vitreous. Crystal Structure: Hexagonal (trigonal). Cleavage: None. Specific Gravity: 2.65.

Rutilated quartz is formed hydrothermally, typically in pegmatites and hydrothermal veins. It forms when titanium dioxide (TiO2) crystals (rutile) grow within a quartz crystal during its formation. The specific geological age varies depending on the deposit, but these processes occur over millions of years as the Earth's crust cools and fluids deposit minerals.

Rutilated quartz is primarily used as a gemstone in jewelry, including beads, cabochons, and faceted stones. Its unique internal patterns make it a popular choice for necklaces, bracelets, earrings, and rings. Due to its aesthetic appeal and durability, it is also highly sought after by mineral collectors.

Also known as Querétaro Diamond or Venus Hair Stone, rutile quartz is highly prized by collectors for its stunning inclusions. The rutile needles can be extremely fine and dense, creating an effect known as 'gold hair' or 'angel hair'. The orientation of these inclusions can sometimes create a cat's eye or asterism effect, though less common than in other minerals.

In the field, rutilated quartz is identified by its characteristic needle-like inclusions of rutile within a transparent to translucent quartz host. The color of the rutile can range from golden to reddish-brown, black, or silvery. Common locations include Brazil (especially Minas Gerais), Australia, Russia, Norway, the USA (Arkansas, Georgia, North Carolina), and Switzerland. For collectors, look for clear quartz with well-defined, aesthetically pleasing rutile needles. The density and color of the rutile can significantly influence its value.