To V or not
to V? That is the question. Whether 'tis nobler in the minds of thou customers
to place upon their marquise a prong in the shape of a V, or dost thou
leavest it exposed to the concerns of the world.
Ok, William Shakespeare I'm not. However, for the bench jeweler, the
question remains. What do you do with this prong in the shape of a V?
Several shapes of stones have pointed ends, including marquise, pear,
heart, and princess. Because these points are often thin and fragile,
it is important to protect them with a prong. This is particularly important
on rings where the stone may be subject to more abuse than in pendants,
earrings, or brooches. Although a standard prong will usually suffice,
a V shaped prong is preferable. A V-prong provides additional protection
and will more securely hold the point of the stone.
Special care is necessary when setting these stones to keep from chipping
or breaking the point. Extensive preparation is necessary and work must
be executed with precision to properly set them. Nothing short of true
craftsmanship can be exercised while attempting to set a stone with pointed
The seat in the V-prong may be cut with a variety of burs, gravers, drill
bits, or files. There is no one best method. The method used will depend
on the situation and one's own preference of tools. The following is the
basic procedure I most often follow.
Using a small hart bur cut a line on the inside of the prong at the height
you want the girdle of the stone. Check and double-check that this line
is at the proper height and is straight and level. In addition to beginning
to form the seat, this line will serve as a guide to base all future cutting
on. If this line is off it will be near impossible to set the stone straight.
This line does not have to be very deep at this point (it can be cut deeper
later); however, do not cut into the prong more than 1/3 the thickness
of the prong.
Next turn the bur 90 and cut a line down the center of the prong. This
cut, along with the first cut, will form a cross-shaped pattern in the
prong. This second cut will allow clearance for the pavilion of the stone.
It is particularly important on the heavier cast V-prongs.
Using a bud bur cut a hole in the center of the cross. Cut no further
than ? the way into the prong. This hole creates the void surrounding
the tip of the stone. Make certain there is a cavity below AND above the
tip of the stone. Putting pressure on the tip of the stone from above
with no support underneath will cause the point to break off.
Finally trim away any excess metal and smooth the seat using a polished
How you cut the seat is not nearly as important as what you accomplish.
The seat you cut in a V-prong must accomplish three items:
1. A smooth even seat which will support the sides of the point on the
2. A void to surround the very tip of the stone.
3. Enough metal must be removed to safely push the top of the prong over
the stone, while leaving enough metal to securely hold and protect the
Once the seat is cut completely, examine it for these items with a loupe
or microscope. First examine the seat, then lay the stone in the setting
and re-examine it. One small bur of metal or ripple in the seat is all
it takes to break the point off a stone.
ALWAYS check the stone with a loupe or microscope before you begin to
push the prongs over the stone. Then check AGAIN once the prongs are part
way down and the stone no longer rocks. The small amount of extra time
taken to check the seats can save a lot of heartbreak (or point break)
With pear or heart shaped stones, bend the V-prong over the stone first.
Then push the remaining prongs over the stone tightening it in the setting.
Setting the stone in this manner allows the stone to move slightly as
you bend the V-prong, limiting the amount of pressure applied to the fragile
tip of the stone.
On marquise shaped stones, bend the side prongs over the stone first,
securing it into the setting. Then the V-prongs are adjusted down over
the points. The V-prong is seen as protection to the fragile points rather
than as something to hold the stone. Setting the stone in this manner
limits the amount of pressure applied to the fragile tips of the stone.
You can use several methods to push the prong down onto the stone. You
can use a prong pusher to gently roll the metal over the stone in the
same manner you would push a bezel down. First, push on one side of the
V, then the other. Alternate sides until the prong is tight against the
crown of the stone.
Chain nose pliers with polished jaws can also be used. Place one jaw
at the top of one side of the V, and the other jaw at the base of the
opposite side of the prong. Gently squeeze one side down a little, then
reverse the position of the pliers and move the opposite side. Work back
and forth until the prong is down on the crown of the stone.
Another method using chain nose pliers is to place both jaws at the top
of the outside edges of the V. Make certain the jaws are at the top of
the prong well above the girdle of the stone. Angle the pliers to match
the angle of the crown facets. Then gently squeeze the pliers together.
As the pliers come together at the point of the V, the jaws will burnish
the metal down onto the stone. Keep repeating the procedure until the
metal is tight against the stone. As you work, excess metal will form
between the pliers' jaws, making a line at the point of the V. You should
remove this excess metal with a file. This method works better on the
thinner die struck V-prongs.
Some jewelers cut a V in the top of the prong leaving two tabs to push
over the stone. Then once the tabs are down the seam is soldered closed.
This method works fine on diamonds, but cannot be used on most color stones.
There is one danger in using this method on diamonds. If excess solder
is used it can flow into the void providing clearance at the tip of the
point. As the solder solidifies it contracts. This can cause the point
to chip or break off.
Once the stone is set, trim and shape the outside of the prongs using
a #6 needle file. Be certain the file has a polished safety edge to avoid
the possibility of chipping or abrading the stone. Trim and clean up the
inside edge of the V with a polished flat graver. Remove the file marks
with an abrasive rubber wheel and polish.
Remember: Caution Is The Better Part Of Valor. If you feel uncertain
while setting, STOP, take a deep breath, check all your steps, examine
the setting with your loupe, then proceed. If you still feel uneasy, take
a break, get a drink of water, relax a bit. Then re-examine the setting
and proceed to finish the setting. Follow these steps and you will not suffer a fate such as Juliet and
her Romeo. "Parting is such sweet sorrow, Farewell, Farewell, I bid