I was looking for a large kunzite for my gemstone collection. Once I asked a seller to send me extra photos, I received the pictures where kunzite is shown in different colours, before and after light exposure.
Does it mean that kunzite can change colour?
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.
Kunzite is famous for its strong pleochroism, showing lighter and more intense coloring when viewed at different angles. It will display intense color variations and color difference when viewed from the top and bottom. It can even display multiple colors or appear colorless.
Kunzite is trichroic, which means that three colors can be viewed from differing angles: pink, clear and violet. Sometimes the color change is limited to shade changes, such as from pale pink to dark pink.
However, when speaking of color changing gemstones, the ability to change color depends on the type of light. A gemstone might look green in sunlight, but red in incandescent lighting. Not quite the same thing, as pleochroism, which involves the same light, but different angles.
In conclusion: Kunzite is not a color changing gemstone