One slip, and thousands of dollars shatter

The men cutting diamonds on West 47th Street, also called Diamond and Jewelry Way, trace their work back to their Venetian ancestors in 700 BC, and through a time when Jews were not allowed to own property or practice law, banking, or medicine. The men wearing dark blue uniforms cut and polish the stones, bringing them to life. Cutting compares with sculpturing and draws on an understanding of solid geometry. One father who has been in the business 30 years is fortunate enough to have his son join him. Few women cut diamonds, although they do deal in the stones.

Many times fathers will give their sons a start in business by buying the poorer-grade rough, or uncut stones, to learn on. It takes years of practice to take on the bigger stones; one mistake can result in a smaller or ruined stone. As it is, diamonds generally lose half their weight by the time the polishing is done.

The very value of the stones makes the men cautious. Security measures come in the forms of cameras, mirrors, buzzer-entry doors, plainclothes guards, and whispers. The doors draw little attention to the business conducted within.

From the time a diamond enters the cutter's shop as rough to the time it leaves as a cut stone, it goes through many hands. The cutter will study the stone and diagram it. He will put a ``window'' in a piece of rough to determine which way he will make the first cut. He may not know what shape this stone will be until he saws it. If the stone is long and narrow, it could become a marquise cut. A round stone could become a pear-shaped or round brilliant.

After the cleaver or sawyer saws the diamond, the girdler rounds off one stone's corners by holding it against another diamond. Diamonds are so hard that they can only be cut by other diamonds. The girdler patiently guides a rod with a diamond attached to one end as the other diamond spins, polishing and shaping the first one. The job requires a feather touch, or the girdler can split both stones.

Once the girdler is done, a cutter will work on the facets. A finished diamond has 58 facets, which act like mirrors. The diamond is held against a wheel that looks like a record turntable covered with diamond dust and oil. The cutter grinds the facets symmetrically onto the stone, constantly slowing the wheel to check his work.

The four major diamond-cutting centers are in New York; Antwerp, Belgium; Tel Aviv; and Bombay. Diamonds are cut in 30 countries.

Cutters have different philosophies about their work. One cutter may like greater angles, another may like more shallow. American-cut stones are considered the best, and not as a matter of pride. The bigger stones are cut in the States.

It is for this subjective difference that many cutters, dealers, and brokers say it is impossible to price all diamonds alike: Two stones the same size and color may reflect two different approaches to cutting them. ``There are no two alike,'' says Lloyd Jaffe of the American Diamond Industry Association. ``They are not fungible, like dollar bills.''

In the early 1980s, Martin Rapaport, a diamond broker and newsletter publisher, started publishing diamond prices, which caused waves in the industry. ``I believe a diamond does not have a fixed price,'' says broker Joseph Schlussel, who publishes and edits the newsletter The Diamond Registry Bulletin.

Mr. Schlussel publishes selling ranges in his newsletter. He says he can sell the industry's benchmark stone, the one-carat, D flawless, for $8,500 - or $16,000. (The D indicates a colorless stone, subjectively termed the ``best'' stone. Flawless means that no imperfections are visible under 10-power magnification.)

``There are minute differences in the stones, such as cuts or flaws. Anyone who says there is a fixed price doesn't know diamonds. It hinges on the workmanship,'' he says.

This same one-carat, D flawless was listed in Mr. Rapaport's list for $17,000 as of Jan. 29, according to Avi Abramoff, vice-president at the Balance Trading Group Ltd. ``This has moved up, because a few months ago it was $14,000,'' he says.

Mr. Abramoff says a price list does not necessarily convey the market's true conditions. Three weeks ago he was looking for a 10-carat, H-colored stone with slight imperfections. He came across three. ``But the asking price was 30 percent above the price list, so prices are only a general indication,'' he concludes.