Kunzite - pleochroism and color-fading effect on Apr 1 2009, at 13:54 in Colour changing Kunzite?
Kunzite is known for its strong pleochroism showing lighter and more intense coloring in different directions. For this reason, it is always cut to show the deepest pink color through the table of the stone. The deeper darker and more saturated colors of kunzite are considered to be the most valuable.
Kunzite may fade in strong light. Some deep pink stones have turned nearly colorless from fading. Although the color-fading effect is not this drastic in most kunzite, it is still important not to expose kunzite gems to strong light (especially sunlight) for long periods. Kunzite is sometimes called "evening stone" for this reason. The color of some kunzite can be restored or intensified by irradiation.