It's Complicated! — Spinel Inclusions

Some of the most desirable spinels come from Myanmar (Burma), as they often have pure red color combined with high fluorescence. Nicknamed "Jedi" spinel by some in the trade, many of these stones contain inclusions consisting of colorless carbonate crystals and complex multiphase negative crystals. Negative crystals are angular cavities within a gem. They often form in the shape, or crystal habit, of the host gem. Complex multiphase negative crystals, as seen here, can contain a sulfur-rich yellow liquid, opaque metal sulfides, transparent carbonate crystals, diaspore fibers and a gas bubble. These complex inclusions are only known to occur in Burmese spinel and serve as a good indicator of the stone's origin.

Clean stones are rare, as the majority have inclusions consisting of colorless carbonate crystals and complex multiphase negative crystals. These complex negative crystals contain a sulfur-rich yellow liquid, opaque metal sulfides, transparent carbonate daughter crystals, diaspore fibers, and a gas bubble. This unique yellow complex fluid inclusion (see above) is only known to occur in Burmese spinel and therefore serves as a good indicator of this origin.