What is the main factor affecting the value of a gem regarding inclusions?

The main factor affecting the value of a gem regarding inclusions is the position and relief of the inclusion. Inclusions are internal features within a gem, and their impact on the overall quality and value can vary significantly based on where they are located and how visible they are.

Inclusions that are centrally located and easily visible can detract more from a gem's appearance than those that are positioned near the edges or in less noticeable areas. The relief of an inclusion, or how it contrasts with the surrounding material, also plays a critical role in determining how much it affects the gem's overall beauty and desirability. If an inclusion stands out sharply against the rest of the stone, it is likely to lower the value; conversely, if it blends in or is less perceptible, its impact may be minimal.

The other factors listed, such as the type of gem, color saturation, and weight, are certainly important in assessing a gem’s value, but they do not specifically address the nuanced way inclusions influence perceived quality and market demand. Thus, understanding the specific characteristics and positioning of inclusions is crucial for evaluating a gem’s overall quality and value.