Faceted Hexagonal Black Onyx · 30 mm

Faceted Black Onyx Hexagon with rose cut, approx. 30×8×4 mm. Six-sided silhouette with faceted dome and flat back. Intense and homogeneous black. The hexagonal geometry provides a modern and architectural profile that departs from traditional organic shapes, ideal for contemporary 925 silver jewelry.

Piece specifications

This specific piece

The elongated hexagon is one of the less common silhouettes in market cabochons; most catalogs focus on ovals, rounds, and teardrops. This shape provides an architectural-reference geometry —like a basaltic column or a miniature honeycomb— that breaks the usual organic language of mineral jewelry.

The uniform black and faceted dome create a concentrated visual presence: the six sides of the perimeter precisely define the outline, and the rose cut of the dome reflects a diffused light that does not compete with the hexagon's edge. It works especially well on enamel backgrounds, in combination with oxidized metals, or in minimalist pieces where geometry is the main argument.

What setting it works for

• Hexagonal bezel (925 silver) — constructing the bezel respecting the six sides of the perimeter is the natural setting for this shape. The result is a piece with geometric coherence between the stone and the metal. Common technique in contemporary goldsmithing.
• Geometric pendant — oriented vertically or horizontally, the hexagon creates a clean and modern pendant profile. Combine with a fine link chain or cable chain to avoid overloading the silhouette.
• Wire wrap — wire wrap on the edges of the hexagon can follow the geometry of the sides, creating a deliberately structural-looking hold.

Black onyx in jewelry tradition

Black chalcedony was used in Roman seals and cameos since the 1st century AD; in 19th-century Victorian mourning jewelry, it was one of the most prized materials alongside jet. The treatment to intensify the black —heating in a carbonaceous solution— has been applied since ancient times and is now completely standardized: GIA and CIBJO register it as a common treatment for market black onyx. It is culturally associated with protection and mental clarity.

The symbolic properties attributed to minerals belong to cultural and historical traditions. They are shared for educational purposes, not as medical advice or a substitute for professional care.

How to recognize genuine black onyx

Black onyx is treated chalcedony: its uniform black is the result of the standard impregnation process. Compared to black glass (bubbles under magnification, very cold to the touch) or obsidian (vitreous conchoidal fracture), chalcedony has a microcrystalline texture visible at 10× without bubbles. Black glass usually has a higher specular luster and significantly greater weight.

Frequently asked questions

Is black onyx treated?

Yes. The intense and uniform black is obtained by heating and chemical impregnation, a standard process for market chalcedony. Declared and normalized by GIA and CIBJO as a common practice for black onyx.

What are the exact dimensions of the hexagon?

Approximately 30×8×4 mm for the elongated hexagon. Measurements are from the factory and may vary ±0.5 mm. If you need exact dimensions for a preformed bezel, measure the received piece before constructing the setting.

Is it difficult to construct a hexagonal bezel in 925 silver?

Moderately. It requires bending the silver wire at six precise 120° angles. It is more complex than an oval or round bezel, but perfectly feasible for jewelers with average experience in bezel construction.

Is there stock of multiple units?

Availability varies. For projects that require several identical pieces, check availability before purchasing.

How do I care for black onyx in jewelry?

Clean with a soft, slightly damp cloth; avoid harsh chemicals, prolonged ultrasonics, and intense heat. Store separately from harder gemstones. Consult our jewelry care guide.

See also: cabochons for jewelry · handmade rings · pendants.