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Spinel · Variety of Spinel

Black Spinel

Opaque deep black with vitreous luster

Black
Optical properties

Optical characteristics

Ref. index
1.712 – 1.736
Luster
Vitreous
Pleochroism
None (isotropic)
Fluorescence
Inert
Origins

Source localities

Myanmar Myanmar: Mogok Valley
Notable

Myanmar produces high-luster black spinel, often found alongside corundum in Mogok alluvials.

40% est. supply
Sri Lanka Sri Lanka: Ratnapura / Elahera
Commercial

Sri Lankan alluvial deposits yield plentiful black spinel, commonly used in commercial jewelry production.

35% est. supply
Thailand Thailand: Chanthaburi / Kanchanaburi
Commercial

Thailand produces and cuts black spinel for the commercial jewelry trade.

25% est. supply
Inclusions

Inclusions & features

Crystals Crystal Inclusions Under 10x loupe: solid, well-formed mineral crystals trapped inside the host gem. They may… Fractures Feathers and Fractures Under 10x loupe: irregular internal surfaces that catch light and appear bright, wing-like, or… Fractures Fingerprint Inclusions Under 10x loupe: curved or wavy lines of tiny dots forming patterns that look… Clouds Pinpoint Clouds Under 10x loupe: concentrations of extremely tiny bright dots that individually are too small… Multiphase Two-Phase Inclusions Under 10x loupe: a transparent irregular cavity containing both a liquid phase and a…
Identification

Instruments used

Dichroscope Reveals pleochroism, instantly eliminates singly-refractive stones 10x Loupe Your most-used instrument, start every examination here Polariscope Determines single vs. double refraction, quick and conclusive Refractometer Measures refractive index, the backbone of gem identification UV Lamp, Long Wave and Short Wave Fluorescence exposes treatments, synthetics, and origin