What term describes inclusions causing light diffraction that resemble a fingerprint?

The term that describes inclusions causing light diffraction that resemble a fingerprint is "fingerprints." This phenomenon occurs when specific types of inclusions within a gemstone create unique patterns that mimic the appearance of actual fingerprints. These inclusions can affect how light interacts with the stone, leading to the distinctive visual patterns that can be observed.

In gemstones, such fingerprints are often caused by liquid or gas inclusions that create swirling shapes or linear features, contributing to the stone's overall character and potentially its value. This distinct appearance is a valuable identifying feature that gemologists use when examining gemstones. While other terms like inclusions, feathers, and silk refer to different types of internal features or characteristics within gemstones, they do not specifically denote the unique light diffraction patterns associated with the term "fingerprints."