Black Obsidian · Marquise Cabochon Pair

Pair of marquise black obsidian cabochons, 14 and 14.5 × 5 × 4 mm, with beveled edge and flat back. Matte black with intense vitreous luster. Hand-cut in our lapidary workshop.

Item details

These specific pieces

The obsidian in these pieces offers an intense and uniform black. When the piece is rotated under light, the vitreous luster shifts, giving a sense of depth in an opaque material. The marquise shape —elongated, with points at both ends— breaks the monotony of a round cabochon without adding complexity to the setting.

The beveled (chamfered) edge here replaces the classic dome: the lapidary chose a flat, faceted geometry to take advantage of the material's total opacity. A high dome on obsidian only reflects light at one point; the bevel allows the silhouette to have visual prominence. The two pieces are from the same rough fragment with identical color and polishing quality.

How obsidian is formed

Obsidian forms when rhyolitic lava —very viscous and rich in silica— cools so quickly that atoms do not have time to arrange themselves into a crystalline lattice. The result is a volcanic glass without a regular internal structure, which produces a conchoidal fracture and a completely uniform polished surface with no visible grain.

What settings it works for

• Bezel setting (925 silver or other precious metals) — the marquise shape fits elongated elliptical bezels; the 5–5.5 Mohs hardness recommends protecting the edges with the bezel
• Statement rings / Pendants with silver settings — the marquise silhouette is ideal for vertical pendants or rings that visually elongate the finger
• Wire wrap — the flat shape with a bevel facilitates perimeter wrapping; black contrasts well with oxidized copper or silver

Obsidian in lapidary tradition

Obsidian was one of the first materials carved by humans: obsidian arrowheads and knives have been found in Paleolithic sites in Anatolia, Mesoamerica, and the Aegean Sea. Mesoamerican cultures attributed ritual value to it and associated it with inner vision and protection. In crystal tradition, black obsidian is considered a stone of grounding and clarity — one that reflects without adornment, one that shows what is without filters.

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 obsidian

Genuine obsidian has a conchoidal fracture: if it breaks, the edges are curved, vitreous, and very sharp. The polished surface is completely smooth with no mineral grain marks. It is opaque to light but reflects with an intense vitreous luster. Imitations in black glass often have visible internal bubbles or a duller reflection.

Frequently asked questions

Has this obsidian received any treatment?

No. No detectable treatment. Black is the natural color of volcanic glass, with no dye or treatment applied. Statement based on lapidary observation; the piece does not include formal gemological certification.

Can both cabochons be used for a pair of earrings?

Yes. Both pieces are made of the same material with identical color and finish. The 0.5 mm difference in length (14 mm vs 14.5 mm) is usually imperceptible in a pair of earrings at normal viewing distance.

How is obsidian cared for?

Clean with a soft, slightly damp cloth. Avoid impacts (hardness 5–5.5 and conchoidal fracture make it fragile to direct impacts). Store separately from harder minerals. See care of your jewelry.

What are the exact dimensions?

Cab.1: 14 × 5 × 4 mm. Cab.2: 14.5 × 5 × 4 mm. As they are hand-cut, there may be a variation of ±0.5 mm in any dimension.

See also: all cabochons · artisan lapidary.