Triangular faceted cabochon of red onyx, 10 mm diagonal, with a flat back. The intense orange-red hue and vitreous luster of the facets create a clean visual center for geometric rings and contemporary aesthetic earrings. Selected from a wholesale lapidary market.
Piece Details
| Mineral |
Red Onyx (chalcedony, microcrystalline quartz — with standard lapidary coloring process) |
| Dimensions |
Approximately 10 × 10 mm. Variation of ±0.5 mm due to hand-cutting. |
| Shape and Back |
Faceted equilateral triangle (trillion cut), flat back |
| Finish |
Mirror polish on facets and back |
| Hardness |
6.5–7 Mohs — suitable for rings and daily wear; protect the triangle's vertices with a bezel setting |
| Origin |
Material acquired from a wholesale lapidary market |
| Treatment |
Standard lapidary coloring process (most commercial red onyx is dyed chalcedony; the orange-red color is not natural in most specimens) |
| Piece Type |
Loose piece (price per unit) |
This specific piece
The uniform orange-red tone is the result of the coloring process applied to very fine-grained chalcedony, which absorbs the pigment homogeneously. The three crown facets are visible from the front and create a movable triangle of light when the piece rotates under direct light.
What mounting it works for
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Triangular bezel setting (925 silver or gold) — the equilateral triangle fits into standard 10 mm bezels.
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Geometric statement rings — the clean geometry works especially well in designs.
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Asymmetric earrings — a single triangular cabochon in a solitaire earring creates a.
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Wire wrap — the flat back and high hardness make the onyx.
How chalcedony is formed
Microcrystalline chalcedony forms when silica in aqueous solution migrates through fissures and cavities in volcanic or sedimentary rock, depositing in layers of quartz crystals only 1–4 micrometers thick. The result is a compact mineral with a conchoidal fracture and a resinous to vitreous luster. The concentric banding visible in many varieties (agate) reflects changes in the concentration of silica or trace minerals during deposition. The lapidary coloring process takes advantage of this micro-porosity to uniformly saturate the stone.
Onyx in lapidary tradition
The term "onyx" comes from the Greek ónyx, "nail" or "claw," due to the translucent appearance of chalcedony in thin sheets. In classical Rome, black and banded onyx was carved into cameos for wax seals and objects of distinction. Pliny the Elder describes it in his Naturalis Historia as one of the most worked stones in Roman workshops. In ancient Mesopotamia, onyx was part of royal funerary trousseaux as a symbol of protection.
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 chalcedony
Genuine chalcedony has a very fine texture to the touch and a consistent vitreous luster. Upon first contact with the hand, it feels noticeably cooler than glass. Dyed glass produces a more plastic sheen and may show microbubbles when held up to the light; chalcedony exhibits an irregular conchoidal fracture. In red onyx with a coloring process, a fresh fracture may reveal the contrast between the dyed exterior and the lighter interior — this is normal and expected in this variety, and does not indicate falsification.
Frequently Asked Questions
Is the red-orange color natural?
In most commercial red onyx, the color is obtained through a standard lapidary coloring process applied to fine-grained chalcedony.
Is it suitable for an everyday ring?
With 6.5–7 Mohs, onyx holds up well to everyday wear. We recommend a bezel setting that protects the vertices of the triangle, which are the most vulnerable points in angular geometries.
Are the facets perfectly flat?
Being hand-cut, there may be a variation of ±0.5 mm in any dimension and the facets may show micro-undulations characteristic of artisanal polishing, which is what distinguishes.
