Which color of star sapphire is typically shallow due to parting?

The typical characteristic of color in star sapphires can be influenced by their internal structure and the presence of rutile inclusions that create the star effect. Black star sapphires are known to have a coloration that appears more shallow due to parting, which refers to the way internal fractures and inclusions can affect the way light interacts with the stone. The deep color of black star sapphires can give an impression of depth, but the way light reflects off the inclusions and internal features may create an illusion of a more shallow hue.

In contrast, blue star sapphires, while known for their striking star-like pattern, typically exhibit deeper and richer tones that aren’t diminished by internal features in the same way. White and green star sapphires also do not exhibit the same level of shading effects from parting as black star sapphires. Therefore, black is recognized for its distinctive traits regarding how the color and the star phenomenon interplay, leading to its classification as typically shallow due to parting.