Cobalt Blue Spinel - An Phú, Luc Yen District, Vietnam - 0.19ct

• Gemstone: Natural Cobalt Blue Spinel
• Species: Spinel
• Color: Vivid electric neon cobalt blue with a bright cyan cast
• Origin: An Phú, Lục Yên District, Yên Bái Province, Vietnam
• Carat Weight: 0.19 ct
• Shape: Cushion
• Cut: Modified mixed cut
• Dimensions: 3.30 × 3.00 × 1.60 mm
• Clarity: Estimated SI1 / Eye Clean
• Treatment: Unheated / Untreated
• Transparency: Transparent

The defining characteristic of this spinel is its vivid electric neon cobalt-blue appearance. The stone exhibits exceptionally high saturation and a bright, open visual character, with cyan-blue flashes appearing as the stone moves.

The absence of an obvious gray or brown modifier is particularly significant. In Vietnamese blue spinel, cobalt is the dominant chromophore in the most saturated blue material, while iron can contribute to a grayer appearance. GIA's study of Luc Yen blue spinel specifically found that increasing iron relative to cobalt produces a grayer color, making the exceptionally clean visual character of highly saturated material an important quality consideration. Gia Education

The designation cobalt blue here reflects the documented characteristics of the material and the recorded locality; definitive confirmation of cobalt concentration in this individual stone would require laboratory chemical or spectroscopic analysis.

Macro and rotational examination reveals a transparent body containing fine internal micro-clouds and scattered pinpoint inclusions. These characteristics are readily apparent under approximately 10× magnification but do not materially interfere with the stone's face-up brilliance at normal viewing distance.

For inventory purposes, the stone is best described as estimated SI1 clarity, rather than represented as a formal laboratory grade.

The cushion modified mixed cut uses a shallow 1.60 mm profile to maximize face-up spread and light return from a very small piece of rough. The result is a stone that presents larger visually than its 0.19-carat weight might suggest.

Minor facet abrasion is visible around the girdle/pavilion junction under macro examination and should be considered when selecting a mounting and during bench work.

The stone is represented as natural and completely untreated / unheated.

Spinel is a durable species with a Mohs hardness of approximately 8 and no cleavage, making it suitable for jewelry applications. Its small size and shallow profile, however, warrant appropriate protection during setting and fabrication.

Recorded locality: An Phú, Lục Yên District, Yên Bái Province, Vietnam.

The broader Lục Yên district is an established source of vivid blue and cobalt-blue spinel. GIA research documents cobalt-rich blue spinel from the district and identifies cobalt as the principal chromophore responsible for the strongest saturated blue colors. Gia Education

The exact mine or pocket provenance of this individual stone should be understood as recorded/dealer-supplied provenance unless independently documented by a laboratory report.

At 0.19 carats, this is not a stone whose significance derives from size. Its interest lies in the unusual concentration of color within a very small volume of material.

Fine electric-blue Vietnamese spinel is itself a relatively specialized collector category, and the Luc Yen district is particularly noted for vivid blue material. GIA has documented that some of the most saturated cobalt-blue spinel from the region occurs in comparatively small crystals, making small but intensely colored examples characteristic of the locality rather than inherently anomalous. Gia Education

For Dante Bianco, the stone is best regarded as a small collector-grade color specimen: compact, intensely colored, naturally occurring, and potentially suited to a highly controlled architectural setting where its color can function as a concentrated point of light.

Independent laboratory verification may be arranged upon request to document species, natural status, treatment status, and, where testing permits, geographic origin and the chemical characteristics associated with its cobalt-blue coloration.

Every stone offered by the House is selected for more than its nominal rarity. Color, proportion, clarity, cutting, material integrity, and the way a gemstone responds to light are considered together. A gemstone must possess a character worthy of being preserved and, when appropriate, incorporated into a future House creation.