Lab alexandrite is grown using the Czochralski growth method and manufactured into laser rods. Lab alexandrite changes color. The crystals are trichroic and the color and color change are determined by what axis the gem is cut on. Alexandrite exhibits red fluorescence and the strength of the fluorescence can change drastically with dopant levels. The red fluorescence in some material is so dominant that it is hard to distinguish a color change. Lab alexandrite has a mohs hardness of 8.5.
Color change flame fusion sapphire looks very similar to lab alexandrite and has a reputation of being sold as lab alexandrite.