Spinel is commonly synthesized for use in the gem industry, but serves little use industrially. The extent of commercial use typically comes from Czochralski-grown Cobalt-doped spinel, which is a common Q-Switching crystal.
Currently most spinel is produced via the Verneuil method and is limited to a small range of colors. Most commonly expressed in pale yellows, greens, and blues. It is important to note that all Verneuil spinel is actually a series between MgAl2O4 and Al2O3 (Spinel-Corundum Series). Alumina is supplied to the feedstock to stabilize the resulting crystals. This action is apparently the reason red spinels are not commonly synthesized. Chromium-doped Verneuil spinels are known to crack and break easily. Most spinels commonly form fractures and defects, but chromium worsens it to a degree that makes it unreasonable to grow. What material exists on the market is limited to rare Czochralski spinels doped with chromium.
