The GIA lab in Bangkok did some analysis of the Mozambique purple garnets and published their findings in the Fall 2016 edition of Gems & Gemology. The material they tested came from a mine in central Mozambique in Manica province close to the Zimbabwe border.

Under cool light these gems display a rich grape hue. But under incandescent light, which has more wavelengths in the red part of the spectrum, these gems display a blazing cranberry color with magenta flashes. Under balanced lighting, they are an intense purple with red flashes.

The material with the best color is found in smaller sizes, under 3-4 carats. Since the color saturation is so intense, larger stones tend to be too dark. Though the highest grade material has come from the Mozambique deposit, both the Tanzanian and Mozambican material display the distinctive color change.