This is the easiest way to set a faceted stone yet devised. No cutting seats or filing prongs. Just turn the stone face down on a semi-hard surface (a magazine works great), push the mounting down over the gem – until it “snaps”.
Check and make sure the stone is level in the setting. If not, a gentle nudge with fingernail should fix it. Check to make sure the prongs are snug against the girdle of your stone. If they are not perfect, gently use some chain nosed pliers and press them across opposing prongs under the stone.
Remember “gentle” is the key, as too much pressure can twist your setting or damage a valued stone. Now you’re done, and have a perfectly mounted stone.
As a rule, Snap-Tites are not made in half-sizes because any given size will accommodate a stone up to one-half larger. For example, a 6.5 mm stone will mount in a 6 mm snap-Tite.
HINT: Place your gem face down on a piece of double-sided tape attached to a magazine - it helps to keep your gem in place for setting.
Gemstone Setting Instructions for Cast Cabochon Mountings, and Back-Set Dangle Settings
Place your gem in the setting. Using a pair of smooth-jawed pliers, gently bend the prongs against your gem.
Gemstone Setting Instructions for Pre-Notched Cast Settings
Place your gem in the setting, making sure it is level. Using a pair of smooth-jawed pliers, gently bend the prongs against your gem - do not tighten completely. It's best to work in an "X" pattern (prongs across from each other). Once you are sure your gem is level, tighten the prongs. If using a setting with accent stones, be sure to set them before setting your main gem.