Oval labradorite cabochon, approximately 40 mm, with dominant electric blue labradorescence. Most of the visible spectrum in this specimen is concentrated in the blue-indigo range, with secondary greens appearing when rotated. Flat, mirror-polished back.
Item Details
| Mineral |
Labradorite (plagioclase feldspar) |
| Dimensions |
~40 mm major axis (unique piece; see photographs) |
| Shape and Back |
Oval, flat polished back |
| Finish |
Mirror polish |
| Hardness |
6-6.5 Mohs — we recommend a closed bezel setting to protect the edge |
| Origin |
Material acquired from a lapidary wholesale market |
| Treatment |
Untreated |
| Item Type |
Unique piece |
This specific piece
The intensity of blue in a labradorite depends on the thickness and uniformity of the internal lamellae. In this specimen, the phenomenon covers most of the surface with high-saturation blue-indigo color — what is described in the wholesale market as Grade A or AAA in blue labradorite. Green flashes appear at oblique angles of illumination.
With a ~40 mm major axis and a regular flat back, this piece is designed for a dominant pendant or a large statement ring. The intense blue pairs particularly well with 925 silver with a satin or polished finish.
How labradorescence is formed
Labradorite is a plagioclase feldspar formed in basaltic igneous rocks and anorthosites. Its optical effect is due to alternating lamellae of composition (albite-anorthite) developed during slow cooling. The thickness of the lamellae determines which wavelength is constructively interfered: thinner lamellae → blues; thicker → greens and golds. Labradorites with dominant blue have particularly fine and uniform lamellae.
Suitable for which setting
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Bezel setting (925 silver or other precious metals) — custom bezel built around the oval perimeter; the smooth finish of the silver highlights the stone's blue without competing with it.
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Pendants with silver mounts — the ~40 mm format is ideal as a focal point for a long necklace or short pendant.
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Wire wrap — an alternative for those who work with wire; the oval contour is receptive to a structured wrap with round silver wire.
Labradorite in lapidary tradition
The Finnish variety of labradorite with dominant blue — known as spectrolite in the industry — has been commercially exploited since the 1940s. However, blue labradorites from Madagascar and Canada are equally valued for their color uniformity.
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 labradorite
Genuine labradorescence is angular: it disappears when the stone is tilted beyond an angle threshold. Glass imitations produce a consistent shine in all positions. Under magnification, labradorite shows visible cleavage on the surface and microinclusions characteristic of plagioclase feldspar. A complementary test is weight: ~2.70 g/cm³ for labradorite, clearly lower than glass crystal (~2.5 g/cm³ for borosilicate but up to 3.5 for lead glass).
Frequently Asked Questions
Is it the same stone as the previous 40mm labradorite in the shop?
No. These are distinct pieces of the same mineral. This variant has dominant blue labradorescence (electric blue-indigo); the other presents a broader spectrum with a blue-green-gold balance. Each piece is unique due to the distribution of its internal lamellae.
What setting is it most suitable for?
For a custom-built bezel in 925 silver. The dominant blue combines particularly well with silver in a satin or mirror-polished finish. We recommend a closed bezel setting due to its 6-6.5 Mohs hardness.
Does it have any treatment?
Untreated. The blue color is a result of the natural internal microstructure. Statement based on lapidary observation; the piece does not include formal gemological certification.
More about labradorite: properties, meaning, and uses. See also: cabochon collection · handmade pendants.
