Watermelon tourmaline 2 faceted stones foil leaf back side. 1 Watermelon slice

A Foil Backed Colorless Quartz Cabochon. Foil backing (or foiling) is a gemstone surface enhancement technique where a thin sheet of metal or other material (sometimes colored) is placed behind the gemstone in order to reflect more light, and/or color, back into the stone and then towards the viewer. A thin piece of foil was placed in the setting behind the stone. Sometimes, but much more rarely, the gem was “painted” with foil. If the stone was a diamond, it brightened the gem. Sometimes color foils were used with colored gemstones to help amp up the color. Basically the purpose of the foil, was to reflect light and add color to the stone.