Square obsidian cabochon with gold sheen —golden reflections on a black background— measuring 17×17×5 mm. Flat back. Unique piece. Selected at a wholesale lapidary market.
Piece Details
| Mineral |
Obsidian (volcanic glass, ~70% SiO₂) with gold sheen effect |
| Dimensions |
17×17×5 mm |
| Shape and Back |
Square with rounded corners, polished flat back |
| Finish |
Mirror polish |
| Hardness |
5-5.5 Mohs — we recommend a closed bezel setting to protect the edges |
| Origin |
Mexico |
| Treatment |
No treatment. The gold sheen is intrinsic to the mineral, produced by oriented magnetite inclusions in layers |
| Piece Type |
Unique piece |
This Specific Piece
The gold sheen of this obsidian is an optical phenomenon of internal reflection: magnetite or iron oxide inclusions oriented in parallel layers reflect light with a golden hue that varies in intensity depending on the angle of illumination. Against the black background of the volcanic glass, the effect is one of maximum contrast. The square format (17×17 mm) reinforces the clean and contemporary geometry of the design.
Obsidian is amorphous volcanic glass: it has no regular crystalline lattice, which gives it its conchoidal fracture and sharp polished edges.
Geological Origin of Gold Sheen
Gold sheen obsidian forms when highly viscous silicic lava cools rapidly without crystallizing into a lattice. Magnetite or ilmenite inclusions are oriented in planes parallel to the magma flow and act as partial mirrors that concentrate reflection in the golden-orange spectrum. The main deposits are in Mexico (Jalisco and San Luis Potosí).
What Setting It Works For
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Geometric pendant in 925 silver — the 17×17 mm square in a thin profile bezel creates a pendant with a minimalist-contemporary aesthetic.
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Statement ring — we recommend a closed bezel due to the 5-5.5 Mohs hardness and the square edges; the metal protects the edges of the piece.
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Wire wrap — an alternative for those who work with wire settings; the straight sides of the square facilitate perimeter wrapping.
Obsidian in Tradition
Obsidian was humanity's first "blade": sharpened by conchoidal fracture, it was used as a knife and mirror in Mesoamerica, Anatolia, and the Eastern Mediterranean before metal. The Aztecs —who called it itzli— made ritual mirrors and ceremonial knives from it. In crystal tradition, obsidian is associated with protection and grounding.
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 Gold Sheen Obsidian
Authentic obsidian has visible conchoidal fracture on its edges and a specific gravity of 2.3-2.6 g/cm³ (lighter than most crystalline silicates). Authentic gold sheen varies in intensity with the angle and does not cover the entire surface uniformly; an imitation in industrial glass with gold foil shows a uniform reflection without angular variation. Under magnification, authentic obsidian lacks the regular spherical bubbles characteristic of manufactured glass.
Frequently Asked Questions
Is the golden reflection a treatment or coating?
The gold sheen is completely natural. Magnetite inclusions oriented in layers during the formation of the volcanic glass produce the internal reflection without any treatment, coating, or added foil.
What setting is suitable for the square format?
We recommend a closed bezel that protects all four edges of the piece. The square edges of obsidian can chip with direct impacts; the bezel acts as perimeter protection. For a pendant, a mounting that covers the side edges is sufficient.
Are the dimensions exact?
Nominal dimensions: 17×17×5 mm. The dimensional tolerance of the cabochon is ±0.5 mm in any dimension.
How to care for obsidian?
Clean with a soft cloth; warm water if necessary. Avoid bumps and drops (glass chips more easily than crystalline minerals of equal hardness). Store on a padded surface. More at jewelry care.
See also: all cabochons · silversmithing · wire wrap.
