A microscope with various types of lighting is the most practical and reliable method to detect fracture filling in diamonds. All of the filled diamonds examined to date have shown flash effects in a variety of colors. Also seen in some stones are evidence of flow structure, trapped bubbles, incomplete filling at the surface, crackled texture, trapped bubbles, an apparent color to the filler, cloudy filled areas, and surface residue. This article is accompanied by a chart that illustrates the various features seen in filled diamonds, plus features observed in unfilled fractures with which they might be confused.
