Black Onyx Marquise Faceted · 29 mm

Black Onyx Marquise Faceted with rose cut, 29×8×4 mm. Navette silhouette with pointed ends and a domed facet design that captures light at multiple angles. Intense and uniform black, flat back. The marquise shape visually elongates the finger and creates an elegant, direct-line pendant.

Piece Information

This Specific Piece

The marquise (or navette) is the most directional of lapidary silhouettes: its pointed ends create a visual direction that elongates the finger when worn as a ring, or the neck when worn as a pendant. Unlike the oval, which can be oriented horizontally or vertically without losing coherence, the marquise has a natural orientation that jewelers deliberately emphasize.

What Mountings It Works For

• Solitaire ring with marquise bezel (925 silver) — the marquise shape in a ring is a classic that visually elongates the finger. Build a bezel with prongs at the ends or a full perimeter bezel. The 6.5–7 Mohs hardness makes it suitable for daily wear.
• Vertical line pendant — oriented vertically with a bail at the top end, it creates an elegant and direct-line pendant. The black contrasts very well with a fine silver chain or square link chain.
• Statement earrings in a pair — two marquise pieces create linear earrings without needing additional weight; the shape itself has natural movement.
• Wire wrap — the marquise silhouette allows for a tight wrap at the points that secures it without obscuring the dome.

Black Onyx in Jewelry Tradition

Black chalcedony was used in Roman seals and cameos from the 1st century AD; in 19th-century Victorian mourning jewelry, it was one of the most prized materials alongside jet. The treatment to intensify and unify the black — heating in a carbonaceous solution — has been applied since antiquity and is now completely standardized: GIA and CIBJO record it as a common treatment for market black onyx. It is culturally associated with protection, grounding, 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 color is precisely the result of the standard impregnation process. Unlike black glass (cold, very dense, no cleavage) or obsidian (vitreous, conchoidal fracture), chalcedony has a microcrystalline texture and irregular fractures.

Frequently Asked Questions

Is black onyx treated?

Yes. The intense and uniform black is obtained through heating and chemical impregnation, a standard industry process for chalcedony. This treatment is recognized and declared by GIA and CIBJO as common practice for market black onyx.

What is the difference between marquise and oval in a ring?

The marquise has pointed ends and a directional orientation that elongates the finger more than the oval. The oval is more versatile (it can be oriented horizontally or vertically); the marquise has a greater visual presence for the same length.

Is a marquise bezel more complex to make?

Yes, slightly. The pointed ends of the marquise require greater precision when constructing the bezel — the metal thins at the ends, and it must be securely set to prevent lifting. It is a common job in 925 silver for jewelers with average experience in bezel construction.

What is the possible variation in dimensions?

29×8×4 mm. There may be a variation of ±0.5 mm in any dimension.

How do I care for black onyx in jewelry?

Clean with a soft, slightly damp cloth; avoid chemicals, prolonged ultrasonic cleaning, and intense heat. More information in our jewelry care guide.