What is cobbing in the context of gemstone processing?

Cobbing refers to the practice of removing heavily included or undesirable sections from a piece of gemstone rough using a hammer or similar tools. This method is often employed to improve the quality of the final product by discarding parts of the rough that detract from its overall appearance and value. By effectively breaking away inclusions or other flaws, cobbing allows gem cutters to maximize the potential of the stone and obtain higher-quality material for faceting or polishing.

This technique is particularly important in the early stages of gemstone processing, where the focus is on preparing the rough for further refinement. It is a skillful and sometimes risky process, as it requires an understanding of the stone’s structure and the areas that can be removed without compromising the overall integrity of the piece.