Rutilated Quartz

Silicon Dioxide (SiO2) with Titanium Dioxide (TiO2) inclusions

Rock Type: mineral

Rutilated Quartz

Physical Properties

Hardness: 7 (Mohs); Color: Clear to smoky quartz with golden, red, or black needle-like inclusions; Luster: Vitreous; Crystal Structure: Hexagonal (trigonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Formation & Geological History

Formed through hydrothermal processes where rutile crystals grow within a quartz crystal as it cools and solidifies in pegmatites or hydrothermal veins.

Uses & Applications

Primarily used in jewelry as gemstones, for lapidary carving, and as high-demand specimens for mineral collectors.

Geological Facts

The needle-like inclusions are often referred to as 'Venus hair' or 'Angel hair.' While rutile occurs in many minerals, its presence in clear quartz makes it one of the most aesthetically prized inclusions in the gem world.

Field Identification & Locations

Identify in the field by looking for translucent quartz crystals containing distinct, hair-like metallic inclusions. Commonly found in Brazil, Madagascar, and the United States (North Carolina). Collectors should look for 'star' patterns or high transparency in the host quartz.

Identified on: 5/11/2026

Mode: Standard