Micro-CT Pearl Testing: Seeing Internal Growth in Three Dimensions
The outside of a pearl can look convincing while its centre holds the most useful identification clues. X-ray microtomography, often called micro-CT, helps laboratories examine these hidden structures in three dimensions without cutting the pearl open. From a flat image to virtual slices A conventional radiograph projects internal features onto a flat image. Structures can overlap in that view. Micro-CT uses multiple X-ray views to reconstruct the interior, allowing the analyst to inspect virtual sections in different directions. SSEF’s 2009 article describes how this approach helped investigate pearl growth features. It highlights difficult beadless cultured pearls, for which a clearer view of the central region can be particularly useful. What can the images show? Cavities, fissures and growth structures can become easier to understand when viewed from several angles. The analyst can ask whether a line belongs to one cavity or whether several different features overlap. This p...