Synthetic alexandrite is an artificially grown crystalline variety of chrysoberyl, composed of beryllium aluminum oxide (BeAl2O4).
Another method is a “floating zone”, developed in 1964 by an Armenian scientist Khachatur Saakovich Bagdasarov, of the Russian (former Soviet) Institute of Crystallography, Moscow.
Bagdasarov’s floating zone method was widely used to manufacture white YAG for spacecraft and submarine lighting, before the process found its way into jewelry production.
Some pulled stones have been seen to change color from blue to red – similar to natural alexandrite from Brazil, Madagascar, and India.
Seiko synthetic alexandrites show a swirled internal structure characteristic of the floating zone method of synthesis.
However, layers of dust-like particles parallel to the seed plate, and strong banding or growth lines may also be apparent.
They appeared to be inclusion-free and under a strong incandescent light in the long direction, asterism could be seen with two rays weaker than the eye.