A shifty gem? Many gems can demonstrate color shift, which is when a gem’s hue appears cooler under fluorescent light and warmer under incandescent light. This is different from color change where the dominant hue of a gem changes, such as from blue to purple, or even more dramatically, from green to red. This stunning, 4.62 carat unheated tanzanite’s color changes from violet to blue. Tanzanite is also trichroic, meaning it can appear to be three different colors, depending on the crystal direction it is viewed from. Sometimes tanzanite can appear to have multiple colors in one gem! Courtesy: @calebbquashen