mineral

Tourmalinated Quartz

Silicon Dioxide (SiO2) with inclusions of Schorl (NaFe2+3Al6Si6O18(BO3)3(OH)3OH)

Hardness: 7 (Mohs scale); Color: Clear or milky white backdrop with needle-like black inclusions; Luster: Vitreous (glassy); Crystal structure: Trigonal; Cleavage: None/Conchoidal fracture.

Hardness: 7 (Mohs scale)
Luster: Vitreous (glassy)

Identified March 29, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Clear or milky white backdrop with needle-like black inclusions; Luster: Vitreous (glassy); Crystal structure: Trigonal; Cleavage: None/Conchoidal fracture.

Formation & geological history

Formed in hydrothermal veins and pegmatites where silica-rich fluids cool. During formation, black tourmaline crystals grow first or simultaneously, becoming trapped within the quartz matrix. Most commercial specimens are from the Neoproterozoic era.

Uses & applications

Used primarily in lapidary arts for cabochons, beads, and sculpture. It is highly valued as a decorative collector's stone and in metaphysical jewelry.

Geological facts

Also known as Schorlated Quartz; the black needles are specifically the iron-rich variety of tourmaline called Schorl. It is unique because it combines the properties of two distinct minerals in one specimen.

Field identification & locations

Identify in the field by the distinct black, needle-like or rod-like inclusions appearing to pierce through translucent stone. Commonly found in Brazil, Namibia, and the USA. Collectors should look for high clarity in the quartz and well-defined tourmaline patterns.

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