What is a Tang?

• A. A tool used to polish facets to a mirror finish.
• B. A device for marking angles on the rough before cutting.
• C. A device that holds a dop and allows a cutter to adjust and maintain a diamond's angle during polishing.
• D. A measurement gauge for diamond weight.

Answer: (C)

The idea being tested is how a diamond is held and moved precisely during the polishing of facets. The Tang is the part of the dop assembly that the faceting machine grips and uses to hold the dop in place while the cutter works. It allows the operator to set and finely adjust the diamond’s angle, then lock that angle so the facet can be cut consistently across all faces. This precise angle control is essential for symmetry and optimal light performance in the finished gem.

So, the Tang is not about polishing the facets directly, marking angles on rough material, or measuring weight. It’s the holding and adjustable interface that keeps the diamond’s orientation stable during polishing.