LEARNING TO FACET
Faceting is a craft which offers many levels of accomplishment, and we have never met anyone who could not succeed at a personally satisfying level, (and often a profitable one as well). The rate at which people progress varies in relation to their aptitudes and learning experiences, but you will make progress and you will find even your beginning efforts will be gratifying. In the long run, some faceters attain Masters ranking by entering competitions; many more involve themselves in selling their gems to a market that is available for the unique custom cutting you will be able to perform; almost all follow the craft for personal relaxation and enjoyment.
There are ample rewards for everyone. Many people are completely self-taught, including some very good faceters. Of course, it is good to have a teacher if possible, particularly in the very early stages--even a few hours of instruction will give you a running start. Almost as good would be a faceting friend whom you could call upon for advice or just to confirm that you are doing the process correctly. As you gain experience you will find that most advanced learning comes from talking to other faceters. If you are all on your own, however, don't fret about it--you can do it.
GETTING STARTED
Not everyone teaches faceting in exactly the same way. Listen to what others have to say (if you know he's an experienced faceter). On the other hand, there's nothing wrong with using this text now, as is, and saving other advice for later.
The cut that will be described here is a Standard Round Brilliant. It is the most common cut in the world. It is a good design for learning basic terminology and basic techniques. After you’ve done it, move on to other designs-- the merit of your faceting equipment is that it allows you to do things that native cutters with primitive equipment cannot do. You will find cutting custom stones is much more challenging and rewarding (including financially).
Now, back to the first-time stone. Having obtained a piece of material examine it to determine what would be the best orientation of the stone so as to maximize the yield. As you go on, there will be other considerations which affect the way you orient the stone for faceting, particularly color and cleavage characteristics But for your first stone, just consider the yield.
THE FIRST CUT – A PRELIMINARY TABLE
Having determined where the table should be, hold the stone in your fingers and using a 360 grit lap (or a 600 Lap if that’s coarse enough to remove the material you want to remove), grind a "preliminary" table--you need a surface large enough for attaching the dop. This surface will provide you with a reliable reference surface for the cutting of the stone.
DOPPING THE STONE
The stone is cemented to a dop--the process is called "dopping". Select a flat dop which ranges between 1/2 and 3/4 of the projected diameter of the stone. Clean both the
stone and the end of the dop in denatured alcohol (obtainable at your hardware store). Wipe these items dry with a lint-free paper towel. Place just enough adhesive on the end of the dop to coat the surface (*see the note below). Bring the preliminary table in contact with the end of the dop. The adhesive we recommend gives you about 30 seconds to position the stone--that is plenty of time and you will find you can position the dop by eye surprisingly well. In your first attempt you may use more adhesive than needed; you need less than a drop. Too much will cause the setting up process to take a longer--if you have applied too much, you can wick it off onto a bit of paper.
Hold the stone and dop together under finger pressure for approximately 30 seconds. Run a very light bead of adhesive around the stone and set it aside for at least five minutes to assure a good bond. Not very difficult. (Do be sure to observe the caution notes on the bottle--this type of adhesive bonds skin very effectively). After the waiting time, tug a bit on the stone to satisfy yourself it has adhered well.
Insert the Dop into the Spindle, so that the chamfer on the dop engages the alignment pin in the Spindle--push it in snugly.
CUTTING THE GIRDLE
The first step will be to cut the girdle. Place a coarse lap(360 mesh or 600 mesh) onto the platen. To preform the girdle set the Angle Dial at 90.00 . Set the Index at 3 (the first setting of the Standard Brilliant Design). Start the lap turning at a speed setting about 6 or 7 (yes, you can slow it down if that speed makes you nervous—later on, you may be speeding it up). Set the Water Tank so that it is dripping at a rate of one or two drops per second, and clip down the edge of the Splashguard so it doesn't interfere with the stone's reaching the lap. Position the Head so there is no danger of the spindle hitting the lap.
Girdle Facets – set Angle Dial at 90.00
96 Index at: 3, 9, 15, 21...etc…steps of 6…to 93
Using the vertical knob, lower the stone toward the lap until it makes initial contact. When you feel it, hear it, and see the Angle Dial readout go over the 90.00 setting, continue to lower the vertical setting a few divisions on the Vertical Knob, and grind a flat—the Angle Readout will read 90.00. As you do that you will be holding the handle, applying a relatively light and consistent downward pressure as you sweep the stone back and forth across the lap surface. You will see when the Angle Dial has returned to 90.00 (and, you will feel and hear when the cutting action stops).
Then index around the Index Gear, repeating the cut 16 times (on a 96 gear the stopping points are 3,9,15…..in steps of 6.., to 93. You may have to lower the vertical position to get the girdle facets to join—to obtain nice even facets. As you work, you can see there is considerable material to remove, but as you reach the stop, come up against it lightly and consistently.
If you want a round girdle (it has gone a bit “out-of-style” these days), you would now place the machine into the "free wheeling" mode and round off the points. It is recommended that the series of flats always be placed on the stone before rounding. (watch the Angle Dial and be sure that the readout finally shows 90.00 all the way around, as you remove the high points)
SHAPING THE PAVILION – BREAK FACETS
Now, the pavilion can be formed – the Break Facets are done first. You are still using the coarse lap, (switch to a medium lap as you approach the target angle—or, use a medium lap all the way—it’s not so slow). Set a speed of 4 or 5 (later on, when you are more comfortable with your faceting, you will--probably--increase the speeds). The water drip, from the Water Tank, is at a rate of one or two drops per second.
Set the Index Gear at 3 (same settings as for the girdle). Set the Angle Dial at 45 degrees.
Set the stone down onto the lap, in the quadrant of the lap nearest to yourself, lower the vertical position a bit (so you get a reading higher than the 45.00), and slowly sweep the stone back and forth from the center to the edge of the lap and back, grinding a flat. Watch the Angle Dial go down—and finally reach the target of 45.00. You can repeat this—and as you get closer to where the facets will join at the tip (the “culet”), switch to the medium lap. You can observe where that depth of cut is getting closer by cutting several of these index positions (say, at 3 and the opposite index, 51)—repeatedly examining the stone as you adjust the depth of the cut
Then, with the medium lap, continue going down in vertical position—repeatedly examining the stone as you adjust the depth of the cut—the vertical setting—until the facets come to a tip at the bottom (or almost--it will be the Main facets that finally form the tip—the “culet”). That establishes the final depth for the Break facets. With the first break facet in place at Index position 3 (and another position too, at 51), move to the next index position. Proceed to add the remaining break facets, in the sequence shown:
Pavilion Break Facets—set Angle Dial at 45:
96 Index at: 3, 9, 15, 21...etc…steps of 6…to 93
SHAPING THE PAVILION MAIN FACETS
In shaping the main facets (the "mains") you will be removing very small amounts of material, Continue with the 600 (or1200) mesh lap. Approach this slowly and carefully since the material will be removed very quickly. Inspect often. The main facet positions are:
Main Facets--Angle Dial setting at 42:
96 Index at: 96 (0),12, 24, 36, 48, 60, 72, 84
As you do this, inspect the stone and observe how the mains develop--after just barely grinding you can see the beginnings of the break facet. This observation helps you
understand the faceting process, and after some experience you will know exactly where a new facet will appear. The mains are cut until they meet the girdle, as shown in the
sketch. Make note of the position of the vertical adjustment.
POLISHING THE PAVILION
The technique of polishing that is recommended here is the use of Ultra Laps (these laps have the polishing medium deposited on a mylar film). This is one particular method—it is fast, allows the use of the abundant water for lubrication, and does not demand too much by way of developing skills (you will use many additional polishing methods as time goes by). Ultra Laps do cause a very slight rounding of the edge of the facet--but when (and if) you get to worrying about that, you will have become a good faceter and know a lot about various polishing methods.
In polishing this first stone, use an Aluminum Oxide Ultra Lap. Flood the surface of the polish lap with water and place the Ultra Lap onto it.. Then tighten the Safety Nut. Press out the air bubbles you see through the mylar--wet the surface of the Ultra Lap and push the bubble out with your fingers. The water on the surface of the supporting lap will be adequate to hold the mylar down while it is used for polishing--adhesive is not needed.Set down the stone onto the Ultra Lap surface—you’ll need to do a little raising of the vertical position to compensate for the Ultra Lap—resetting the target 40.00. Having done that—the facet on the lap—the angle setting at 40.00--back off the fine adjustment screw about a half turn. The 40.00 reading is maintained by the stone on the lap surface. Turn on the motor and set a slow speed--2 or 3 on the speed control dial. Polish in the same way you had been previously grinding, -- you can bear down to speed the polishing (you may see some fluctuation of the set 40.00—reading some lap error—that’s OK)..
Lift the stone to inspect the surface-- you need to position the lap so the light glances off the surface and allows you to see the grinding scratches. You will see the polished surface as it gradually develops. Don’t settle for less than an excellent polish—NO scratches. If the facet is being stubborn about polishing, you can try reversing the direction of the lap—that often helps.Having completed the polishing on one facet, continue with the others, and having completed the main facets go on to the break facets. Note that you are polishing in reverse order to the grinding sequence. As you use the Ultra Lap you will wear away the polishing medium, or it may seem to slice off in places. You can continue to use the Ultra lap as long as there is some area in which to polish--running the stone over a bare or bumpy spot does no damage. The individual Ultra lap should take you through at least several stones.When you finish polishing the last break facet, you have finished the pavilion. Make a last inspection to satisfy yourself with the quality of the polish. You are ready to Transfer the stone--cementing the pavilion onto a new dop, so that the Crown can be completed. Remove the dop/stone from the spindle.
TRANSFERRING
Read the section on the Transfer Fixture which explains how the dops are set into the fixture. In setting the dops into the fixture, see that the key (chamfer) on the dops are firm against the edge of the pushers", aligning the dops radially.
Set the new cavity dop into a V-block of the Transfer Fixture. Select a cavity dop which covers about 2/3 of the pavilion. Tighten the clamp on that dop. Into the opposing V-block, set the initial dop. Tighten the clamps so that it allows the initial dop to slide when pushed on by the "pusher". Be sure the surface of the cavity dop is clean, and apply a drop of adhesive (or less than a drop--not too much) to the holding surface. Slide the initial dop--pushing it with the "pusher" to maintain its radial position--so that the pavilion is pressed firmly into the cavity dop, and lock the position by tightening the clamp on the initial dop, with the stone under some pressure into the cavity dop. With a toothpick (or whatever) put a small fillet of cement around the stone where it exits the cavity dop. Set the Transfer Fixture on end, the old dop side down--and wait. This is a good time to get a cup of coffee, or tea -- 10 minutes will probably be sufficient for the adhesive to set up, but longer is better.
When you remove the stone, do it carefully--loosen the clamps and get them out of the way-- you now have cavity dop-stone-flat dop, and the original flat dop has to be removed. It's a complicated-sounding instruction, but it's easy: you need an alcohol lamp, a small damp cloth, and small pliers. Light the alcohol lamp. Hold the stone with the damp cloth (to keep the stone cool when heat is later applied), with the cavity dop resting in your palm (avoiding a stress between the stone and the cavity dop), and hold the old dop in the flame. As the dop warms, hold the stone firmly in your fingers (with the damp cloth), and use the pliers to apply a side pressure to the heated dop--and at some point the dop will separate from the stone--it sort of pops off. (In this process, don't make the mistake of removing the wrong dop(!)--a message from the Voice of Experience).
You are ready to facet the Crown. Insert the dopped stone into the Spindle and lock the position.
CONFIRMING ALIGNMENT WITH THE PAVILION FACETS
The Crown Facets are usually cut to align with the Pavilion facets--the keying arrangement will provide a reasonable alignment, but some adjustment may be needed. Use the Index Vernier. To check the alignment, place a 1200 lap on the platen, set the index position of a facet, set the angle at about 85 and with the lap turning slowly, slide the stone across the lap. If the resulting mark is parallel to the edge of the girdle on the pavilion side, you have verified the alignment. If some amount of out-of-parallel is observed, make a correction by rotating the Index Vernier. Having completed the alignment, you are ready to proceed with faceting the crown.
FORMING THE CROWN – BREAK FACETS...
Proceed in a way similar to the faceting of the Pavilion, use the coarse lap only for removal of much material—finish setting the facet with the medium (graduated to a pre-polish) lap.
Proceed cautiously and inspect often.
Break Facets –set the Angle Dial at 52˚
96 Index at: 3, 9, 15, 21...etc…steps of 6…to 93
Cut the break Facets so that they meet at points along the girdle leave a thin polished girdle of 2 or 3% (this is a guess--don't worry about it--your judgment in this will improve with time)-
remember, it was polished previously.
CROWN MAIN FACETS
Again, proceed cautiously and inspect often.
Main facets – set Angle Dial at 40 degrees
96 Index at: 96 (0),12, 24, 36, 48, 60, 72, 84
Cut the Main Facets so that they meet at points along the girdle.
STAR FACETS
Again, proceed cautiously and inspect often.
Star Facets - set Angle Dial to 25 degrees
96 Index 6,18,30,42,54,66,78,90
Cut the Star Facets to meet the points of the Break Facets.
POLISHING OF THE CROWN FACETS
Polishing of the Crown Facets is done in the same way as the polishing of the Pavilion, and again, in reverse order. When you have finished polishing the Crown Facets, you are almost there-- the table is what remains.
THE TABLE.
Remove the dopped stone from the spindle. Place the Tabling Adapter onto the spindle (read the section about the Tabling Adapter).
Completing the Table. When you become more skilled you will find the rough table that was put on for the initial dopping is very close to the final table position. In this first attempt you will probably find there is still significant material to remove, and that you need to use the 600 lap (or the 1200 lap) to get to the final position of the Table Facet. Grind the stone to the final table position--and polish as with the facets. The table, compared to the other facets, is a very large facet and patience is needed in the polishing. Because of the relatively large surface areas, the polishing operation can be noisy--a squeaky noise (extra water with a few drops of detergent can be helpful). Steady firm pressure and slow lap speed will reward you with a well polished table--and a completed stone.
Remove the stone as you did after the first dopping--and you have it.
