Which two elements are primarily responsible for color change in gemstones?

Chromium and vanadium are the two elements primarily responsible for color change in gemstones because they can significantly alter the absorption of light in mineral structures. When these elements replace other elements in the crystal lattice of a gemstone, they can impact how the stone interacts with light, leading to noticeable changes in color under different lighting conditions.

For example, chromophore elements like chromium are known for inducing vibrant colors in stones like emerald, while vanadium contributes to the color play in gems such as alexandrite, which exhibits a dramatic color change from green in daylight to reddish-purple in incandescent light. This ability to switch colors is due to the way these elements affect the electronic transitions of light in the mineral structure.

Other elements like copper, iron, nickel, manganese, beryllium, and titanium may influence color in various gemstones but do not primarily account for the dynamic phenomenon of color change in the same impactful way as chromium and vanadium do.