Other commercially extracted minerals include corandum, garnet, quartz, marble, alexandrite and diamonds. Because of its color-changing quality, this kind of garnet resembles Alexandrite. Colour change is most commonly found in alexandrite, a variety of chrysoberyl gemstones. Alexandrite in sizes over three carats are very rare. The largest producer of jewelry quality laboratory-grown alexandrite to this day is Tairus. At Vanderbilt, there exists a Raman shifted system pumped by an Alexandrite laser. The resulting "Alexandrite" glass remains a signature color of the Moser glassworks to this day. Hydrothermal lab-grown alexandrite has identical physical and chemical properties to real alexandrite. The Inamori synthetic alexandrite had a cat's eye variety, which showed a distinct color change. An alexandrite cat's eye is a chrysoberyl cat's eye that changes color. This has not been reported in natural alexandrite. For alexandrite to form, some chromium would also have had to be present.