What does the term “glassie” refer to in diamond terminology?

The term “glassie” in diamond terminology refers to a well-formed octahedral crystal. This designation emphasizes the quality and clarity of the crystal structure, indicating that the diamond has developed in a way that is both aesthetically pleasing and structurally sound. Octahedral crystals are one of the most common forms in which natural diamonds are found, characterized by their symmetrical, geometric shape.

A well-formed octahedral crystal typically showcases the natural beauty of the diamond, enhancing its optical properties and perceived value. This terminology helps gemologists and buyers alike identify diamonds that possess desirable characteristics. In contrast, other choices like poorly formed crystals, inclusional diamonds, or synthetic diamonds do not carry the same positive connotations as a glassie, which represents the peak of crystal formation in diamonds.