"It's best to start out with glass or quartz," Bill explained, "because of the cost and availability of material. The rough has to be larger than the finished piece because at least a third of it is lost in grinding."
He had preformed (that is, roughly shaped) and "dopped" (or securely attached) a smoky quartz onto the "quill," the arm which fits onto the faceting machine, after which the preformed stone is slowly shaped to the contour of the finished piece. We were going to make a "standard brilliant"--a popular cut and quite a common faceting style for diamonds. As I soon discovered, smoky quartz has a hardness of 7 on the Mohs scale and that fact translates to satisfying brilliance in a faceted stone.
For those of you who are new to faceting, as I was, dopping is the process of securely attaching the gem rough to a metal dopstick with glue or wax. The end of the dopstick to which the gemstone is attached may be flat, V-shaped or conically recessed to accommodate the shape and portion of the stone being attached to it. The dopstick is then inserted and secured in the "quill'' (a chuck-like device) of the faceting machine. Cutting a stone typically involves dopping it to a first dopstick and then cutting and polishing the facets on one side of it. When the first side is completed, the work is turned over in the course of being transferred to a second dopstick.
My next task was to become acquainted with faceting terms; the art of faceting has its own vocabulary. The top part of the gem is the "table," which is the top surface of the "crown," graduating down to the "girdle," which divides the stone from its lower "pavilion," tapering to the bottom point, called the "culet."
The diagram of a faceting design is the formula used to cut facet angles which follow transposition charts conceived by the designers who came up with the different basic cuts "brilliants," "ovals," "marquises," etc. Classification of different facets are "mains," "stars" and "breaks," unless the cut is an unusual one.
Once you're comfortable faceting glass, the next step is to try a quartz crystal. Shown right is a 31mm x 51mm stone cut from quartz.
Gem materials vary in the quality of the light they can refract. Statistical tables of gems' refractive indices and critical angles are found in faceting guides. Quartz, for instance, has a refractive index of 40.5 degrees, and is commonly faceted at 43 degrees for the main culet angle and 42 degrees for the main crown angle.
Bill pointed out the various parts of his Fac-Ette machine, which he says he likes because of its precision. As a retired electrical engineer, Bill is, by nature, very meticulous in his work.
"You know how engineers are," said Bill's wife Peggy, with a smile, explaining that a lot of Bill's jewelry is actually made for her.
The main parts of a faceting machine are the ups and downs, and the facet angle controlling the quill as it is lowered to the rotating lap for cutting. The speed at which the lap rotates is adjustable on most machines. Water drips onto the lap from a volume-controlled container to keep the cutting process cool so the stone is not damaged by overheating.
Each diagram follows a transposition chart, which is for five-, six- or eight-sided symmetries, guided by various numbered index gears to set the cut. Symmetries are based on the division of a circle, much like one might divide a pie in five, six or eight pieces. Then, within the outer circle, are inner-division circles and each cut of the "pie" gets smaller by this division.
The vertical line is the "I.D.," the index-division line. It is a very wise idea to recheck each setting before cutting.
The standard brilliant has 57 facets--the Hope Diamond has 58, plus two extra facets on the pavilion and on the girdle--and three different steps to change the angles. The pavilion is faceted first. Facets must meet at a point (giving rise to the phrase "meet-point faceting").
Starting with a 180-grit lap, each step is repeated with the 360-, 600- and 1,200-grit laps respectively. After inspection of the facets meeting at adjacent facet points, it's time to polish each facet with a compound called cerium oxide, going through all the steps again.
Bill had certainly been right when he'd told me, "It takes time."
Not only that, but it also takes close scrutiny to change the angles for each subsequent step. Mistakes can be all too easily made, as each step is based on millimeters of each angle. To save eyestrain, the faceter uses a close-up magnifying aid such as the OptiVisor(R), which can be worn on the head to keep both hands free. (R&G Editor's Note Many faceters prefer to use a 10X triplet loupe or a special loupe attachment for their eyeglasses which is capable of magnifying at 10X or higher power for even greater magnification.)
I watch a bit of TV while faceting, which eases the monotony during long periods of grinding and polishing. It offers a chance to look away now and then, to avoid eyestrain. And I've been able to catch up on a lot of news and movies, while being productive at the same time.
"Bill concentrates entirely on what he is doing," said Peggy, "and you can't disturb him for anything." Maybe, I thought, that's why he's so good at it!
When the pavilion is finished, the gem is then transferred to another dopstick with a transfer fixture, in order to make the crown. It is exciting to know that the gem is half-finished and well on its way to becoming a faceted beauty!
Transferring the gem from the first dopstick to the second is tricky and certain steps must be carefully followed so that the gem's crown will coincide with the girdle and pavilion. Getting the two dopsticks together to make the transfer takes precision of alignment. (R&G Editor's Note This matter has been thoroughly addressed and demystified by Gerald Wykoff in recent issues of R&G.)
Once that is done, the cutting of the crown begins, with steps changed to the critical angle for the crown. The process is repeated with each changing of the lap, to the final polish.
After the faceter inspects the gem, and is satisfied that all is well, the stone is removed from the dopstick for cleaning in acetone and then with dish-washing liquid to let the dazzling sparkle show through. The sparkle--scintillation and brilliance--is a function of a number of factors, including the perfection of the polish applied to the facets; the number, placement and angles of the facets; and the refractive index of the material from which the stone is cut.
Convinced that I wanted to do more faceting, I bought a faceting machine of my own. There are several on the market. The machine is the most expensive item the faceter needs, but it only requires minimum upkeep. Once a neophyte faceter graduates from glass and quartz, he or she might wish to venture into faceting more expensive gem material.
"I like synthetic material," Bill told me, "because of its clarity and lack of impurities and fractures."
Bill estimated that it took about five hours to facet our first smoky quartz. My solo attempts have taken longer but, then, I'm just a beginner. It goes faster with experience. Even so, I heartily recommend that you find an experienced faceter like Bill to help you get started, and to share the joy in your triumphs. Seeking out an experienced faceter to help you through the first stone or two is definitely the best way to get started. Clubs offering faceting classes and programs are ideal vehicles for getting started with faceting.
Perfect Transfer Index
Table of Contents
With an Experienced Guide, You, Too, Can Bring Gemstones to Life!
Rock&Gem Feature Article - Story and Photos by Ruth Chin
Once I had seen the famous Hope Diamond at the Smithsonian Institution, my curiosity knew no bounds. How do people actually facet gemstones, I wondered. A deep yearning came over me to learn how to turn a piece of gemstone rough into a thing of beauty--one that would dazzle the eyes. "It takes time," said Bill Dutton, a man of few words and the master of faceting at the Muncie, Indiana, Rock & Gem Club. He's been faceting since 1954, when he tired of making cabochons.
I was so eager to know how faceting is done that Bill offered to show me.
"First," he suggested, "get books and read about how to do it."
At left, Master of Faceting Bill Dutton at work, meticulous and totally focused on the task at hand. Interrupt him at your peril, advises his wife!
I learned that ads for such books can be found in lapidary magazines and catalogs and, often, the books themselves are available at rock shops and rock and gem shows. They can even be borrowed from your local public library. But, according to Bill, "To own a good faceting book is to always have it on hand for reference."
I took his advice and started reading about faceting. I learned that, long ago, explorers had roamed the world, seeking precious stones. Once having made their historic journeys--and subsequent conquests--they took gems as booty for the king or queen who had sponsored their particular expeditions. Jewelry was then made from these precious gems, but just who was the first to facet gemstones will, no doubt, always remain an unanswerable question, the answer lost to history.
Faceting is known to have been done in India long, long ago, but certainly not with anything like the fancy machines we use today. Those early faceters held each stone by hand during grinding and polishing. This practice is still in use in some Third World countries even today.
Venice, Italy, had become an important center for the arts by about A.D. 600, and the cutting of jewels is known to have been done there at that time. Louis de Berquem of Brugge, Belgium, is credited with having created, in 1458, the first brilliant-cut diamond (i.e., the typical diamond cut we are so familiar with today). Today, Antwerp (also in Belgium) is the world's center of the diamond and precious-gem trade.
Learning a bit of the history of faceting only fueled my desire to learn how to facet on my own. I poured over Faceting for Amateurs, by Glenn and Martha Vargas. In this great "how-to" guide, every detail from start to finish is fully described by the authors, a husband-and-wife teaching team.
By reading how-to books, anyone can easily decide whether or not faceting is their cup of tea, even when taking time and money into consideration. To some, faceting may look tedious, and it does take patience. But the more I read, the greater was my desire to try it.
Bill was ready to show me how to facet on his Fac-Ette machine.