How is mottling best described?

Mottling is best described as a coloration pattern in gemstones. This phenomenon occurs when there are irregular patches or spots of different colors or shades within a stone, creating a unique visual effect. Mottled patterns can result from variations in mineral composition, inclusions, or the way light interacts with the crystal structure of the gemstone. This characteristic can enhance the beauty and individuality of a gem, making it appealing to collectors and enthusiasts alike.

Other choices, such as a cutting technique, a type of synthetic gemstone, or a polishing method, do not accurately capture the essence of mottling, which is fundamentally about the coloration and appearance of the stone rather than physical manipulation or formation processes. Understanding mottling helps in the evaluation and appreciation of colored stones, distinguishing them based on visual characteristics.