mineral

Black tourmaline pendulum

Schorl, a sodium–iron tourmaline; approximate formula NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

AI-generated identification · may be incorrect

Opaque black to dark gray, vitreous to resinous luster, commonly striated; Mohs hardness 7–7.5. Tourmaline has a trigonal crystal structure and poor cleavage; this specimen is shaped and polished as jewelry.

Identified October 7, 2026More mineral →

Explore Black tourmaline pendulum in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Tourmaline crystallizes in boron-rich granitic pegmatites and some metamorphic rocks, typically during late stages of magma cooling. Its age depends on the deposit and cannot be determined from the image.

Uses & applications

Used for jewelry, decorative objects, and mineral collecting; pendulums are also sold for divination. Schorl has limited industrial use compared with other tourmaline varieties.

Geological facts

Schorl is the most common tourmaline species and is strongly pleochroic in suitable crystals. The pictured object appears to be a polished pendulum attached to a metal chain, not an unworked crystal.

Field identification & locations

Black color, high hardness, and lengthwise striations on rough crystals help identify schorl; it occurs worldwide, including Brazil, Afghanistan, and the United States. A polished pendant cannot be confirmed by appearance alone.