• Refining - purifying metals..

  • Refraction - the bending of light as it passes through a gemstone.

  • Relief - the contrast between the inclusion and the gemstone.  A good example of this would be a lower clarity grade diamond that has eye visible inclusions (the internal characteristics).

  • Rhodium - is a metal in the platinum group.  It is often used as a platinum alloy.  Its purpose is to harden the platinum to give it greater durability for jewelry.  The most common percentage mix of rhodium in jewelry is 95% platinum and 5% rhodium.  It provides a non-tarnishing electroplate with high reflectivity.  It gives the gold a high bright shine when polished.

  • Rough -  an uncut gemstone.