Six-sided obelisk — Black tourmaline · 11 cm

A deep black striated with vertical grooves, with a distinctive glassy luster on fresh faces.

An obelisk with even faces, polished along every edge — a form inherited from Egyptian architecture, where it marked the passage of the sun.

In tradition. The most classic of protective stones: tradition credits it with filtering and absorbing, particularly near workspaces.

Use & upkeep. It sits as well on a bookshelf as on a ritual tray; its verticality alone creates a visual anchor. Dust with a dry cloth. Sharp edges mark if knocked.

• Also called schorl, it is piezoelectric — it takes on a static charge when heated or compressed.
• Indicative size: 11 cm
• A natural piece: shade, veining and dimensions vary from one example to the next

A decorative object for personal practice. It is no substitute for medical advice or treatment.