When a portion of a diamond's original rough surface is retained, what is this feature called?

The feature that retains a portion of a diamond's original rough surface is called a natural. Naturals are areas on a diamond that have been left uncut and preserve the original surface of the rough stone. This characteristic can serve as a unique identifying trait for the diamond, often adding to its individual character and sometimes even its value.

During the cutting process, most of the rough surface is removed to create a polished gemstone that showcases its brilliance and fire. However, leaving some of this original surface intact, known as a natural, can create a visual contrast with the polished facets and can also be appreciated by certain collectors or gem enthusiasts for its natural beauty and connection to the stone's origin.

The other terms listed refer to different aspects of a diamond. Polish describes the smoothness of the diamond's surfaces created by the cutting process. Facets are the flat surfaces that are intentionally cut into the stone to enhance its light performance. The girdle refers to the outer edge of the diamond, which separates the crown from the pavilion and can influence the overall appearance of the gemstone.