Back to Ganoksin | FAQ | Contact

Prong setting a diamond

Dear Orchid friends,

I am standing on the exciting brink of making my first attempt to
prong set a diamond in a gold ring setting purchased from Stullers. I
have been prong setting other less valuable stones for a while now,
practice. But now this will be my first time to prong set a rather
valuable yellow diamond. The diamond measures 5.23 mm in diameter and
3 mm deep. I am setting it in a “Trellis” setting.

Here are two pictures of this setting with two different sized stones
set in it so you can appreciate the construction of the prongs, if
you are not already familiar with this type of setting:

My question is, since this setting only has 4 prongs, will the
diamond be secure in the prongs or do I need to do something extra
like soldering/adding a wire around the inside of the prongs to
fortify the= setting?

I don’t want to set the diamond and then have it fall out when the
ring is worn.

Any tips would really be appreciated.

Laura H. Hastings


your first attempt in claw/prong setting is fantastic…you need no
other additional claws/prongs to add to the simple design. Keep it
plain and simple…but secure!

I would prefer if the claw tips are not extending too high above the
’table’ facet. If they are, she will catch the tips and somehow move
back the claw from its ‘resting’ position. and you really don’t need
this problem. next point is to file the tips round, or use a 'cup’
bur or a #77B" to keep the claw tips nice and uniform… for the claw
height,it is recquired to keep the finished claw at a height
inbetween the “table and the girdle”…but what size of cup bur
should you use? easy, the bur size should extend slightly over the
thickness of the claw itself…and hold the bur at an angle not
exceeding 45 degrees ‘away’ from vertical…for final finishing
prior to polishing, I use a pumice wheel of 180 grit to remove any
little marks left by a bur or ???..have lotsa fun…


Well set, you should have no problems with this type of setting at
all. This means a correctly cut seat, in full contact with both the
pavilion and the crown, with nicely rounded prong tips that will not
catch. (This assumes you leave @ 50% of the prong thickness at the
girdle and your tips rise @ 25-40% of the girdle height, roughly,
depending on stone size) I set this style of ring frequently, and
except in the few cases of serious customer abuse they seldom
loosen, and I have never had someone lose a stone from this setting.

Hi Laura

Two ways (that I can think of off the top of my head) to do this. One
way is to use a setting bur roughly 70% the size of your stone to
make a seat. Depth being just a but mire than the distance from the
table of your stone to the girdle. This would allow you sufficient
prong length to “bend” the tips onto the crown of the stone. Make
sure you leave 50% minimum prong thickness after you cut the seats.
This method seems to “feel” safer in terms of holding the stone. The
second way is to make seats using a bearing cutting bur. Again 50%
max depth, 70% bur size. You’ll need to be carefull to cut the seats
even to each other. Go down just a little deeper than the distance
from the table of your stone to the girdle. I like this way better
as the finished job results in nice round prong tips and you havent
even cleaned up with a cupping bur yet! The way to tighten this type
of setting is to slowly squeeze two prongs together, then rotate the
ring 180 degrees and squeeze the other two together. Next turn the
ring 90 degrees and squeeze the two prongs together again bringing
the prongs back in line. Rotate the ring 180 degrees again and
squeeze. Youu should have a fairly tight stone at this point. If
not, repeat the steps. You must make sure that your seats are cut at
proper angles to the crown and pavillion of the stone for a tight,
rock-free fit. The other reason I like this type of setting better
is that while you are moving the prongs closer and closer to the
stone, you are also work hardening the metal, thereby making the
prongs harder to pull off the stone.

Stanley Bright

Baltimore, MD