Colour-Change Cobalt Spinel is an exceptionally rare natural gemstone prized for its vivid saturation and striking dual personality. Colored by trace amounts of cobalt combined with chromium or iron, this remarkable mineral shifts from a vibrant, electric blue in daylight or fluorescent lighting to a rich purple or reddish-magenta under incandescent light. Rated at an 8.0 on the Mohs hardness scale, its exceptional durability and single refraction give it a crisp, bright luster—making clean, high-carat specimens from top deposits in Tanzania, Sri Lanka, and Vietnam highly coveted by gemstone collectors worldwide.
