When discussing colored gemstones, what is meant by "color zoning"?

"Color zoning" specifically refers to the presence of areas within a gemstone that exhibit different colors. This phenomenon can occur due to a variety of factors during the crystal formation process, such as variations in mineral content, changes in environmental conditions, or even the presence of inclusions. When examining a gem, those different colors can be visibly distinct, creating bands or patches that can enhance or affect the overall appearance and perceived quality of the stone.

Understanding color zoning is important for gemologists and consumers alike because it can influence the value of the gemstone. While certain zoning might add to the uniqueness and beauty of a gem, excessive or unappealing zoning could detract from its desirability, especially if one color is preferred over another. In the broader context of gemstone appraisal, recognizing and assessing color zoning helps in making informed decisions about quality and authenticity.