Which natural element is a common inclusion in emeralds?

Emeralds, a variety of the mineral beryl, are known for their rich green color, which is primarily due to chromium and vanadium. A common inclusion found in emeralds is actinolite. This mineral manifests as needle-like or elongated inclusions, providing a unique characteristic that helps gemologists identify emeralds. The presence of actinolite can affect the overall appearance and value of the gemstone, but it is a recognized and natural part of many emeralds.

In contrast, gold, pearl, and quartz are not typical inclusions found in emeralds. Gold is a metal and does not relate to the formation of emeralds, while pearls are organic and do not occur in gemstone formations like beryl. Quartz may be found as a separate mineral or rock but does not serve as a typical inclusion within emeralds. Thus, the identification of actinolite as a common inclusion highlights an important aspect of understanding and evaluating emeralds in the context of colored stones.