News

Advanced Search

Japan Market Report

Nov 3, 2000 9:58 AM   By Kazuko Ito
Email Email Print Print Facebook Facebook Twitter Twitter Share Share
Beyond Excellent

By Kazuko Ito

A new diamond cut, promoted by its Tokyo creators as revolutionary, is making its first appearance on the market. When viewed face-up, the finished diamond is said to look much whiter than it actually is. An H color, for example, looks like a D color. This is not a treatment, coating nor HPHT. The new cut is named "Over Excellent" (OE) because it is designed to go above and beyond anyone’s concept of the well made stones available today, that carry names like Excellent Cut, Hearts & Arrows or Ideal Cut.

The new OE cut is derived from a formula totally different from Marcel Tolkowsky’s ideal proportions. "It has something to do with critical angles of light wave traveling through the diamond," says Yoshinori Kawabuchi, President of Hohoemi Brains, Inc. of Tokyo. "Our research consultants succeeded in mathematically formulating the cut of diamond to bring the ultimate brilliance by adopting the nature of critical angles of light refraction inside diamond. By doing this, certain light wavelengths such as red or yellow can be subdued and a more desirable wavelength such as blue can be enhanced. Also, cuts are engineered in a way that returning light from the diamond focuses on the crown so that the stone gives more brilliance, more scintillation and more dispersion of light than the traditional ideal cut."

Like the designation "ideal," OE is confined to the round brilliant cut. The newly invented OE cut is a round brilliant stone with 58 facets, much like any other round brilliant stones. The secret, according to the creators, is in the surface volume. Compared to the traditional round brilliant, the diameter of the OE stone is about 17 percent longer and total surface area of the crown is 37 percent larger. Pavilion depth is shallower than regular round brilliants. In other words, the finished OE cut is a flat stone and appears larger compared to a regular round brilliant of the same carat weight. Patent is pending on this specific formula that Hohoemi Brains discovered, and until the patent registration is complete, which could take a year to a year-and-a-half, the company is refraining from revealing the formula.

The brilliance does not result from the crown angles, nor pavilion angles. The table size is also irrelevant. One can collect a number of OE cut stones and place them on Sarin’s Dia-mension; the angles and measurements will not tell the whole story, says Kawabuchi.

Fire Hides Flaws

In the finished OE cut, large imperfections become less visible to the naked eye because of the strong brilliance. The milky or hazy looks of a strongly fluorescent stone is also overcome by the OE’s brilliance.

The OE cut has other advantages. Large stones are rarely cut to ideal proportions, because that cut’s small table makes the stone look smaller than it actually is. OE cuts look bigger regardless of the size, and their strong brilliance makes the bigger stones more appealing.

A Lab’s View

Yoichi Horikawa of Central Gem Laboratory recently had a chance to examine the OE cuts. He reported that the stones looked their best when viewed face up from about 12 inches away. When set in jewelry, they will certainly look more brilliant and whiter, Horikawa assured. But when the stones are sent for grading, they will not get any better color grades than they actually deserve, because stones are examined at a side angle for body color.

Making Market Sense

The OE cuts may receive a poor over-all cut grade because of their shallow depths, Horikawa points out. "And more importantly, how does the market determine the prices of OE cuts when they diverge from the independent labs’ grades criteria?" asks Masahiko Akaike of Orient 4Cs, a dealer/wholesaler.

As seen in the Rapaport Diamond Price List, the prices of diamonds are determined by 4Cs: carat weight, color, clarity and cut. "Cut is the most challenging of the 4Cs," admits Kawabuchi. "But I have always wondered why the slight difference in grades makes such a difference in prices in the market place. Take VVS1 and VVS2, is there an objective definition between these two grades? Take E color and F color. Sometimes the difference is so slight that even the experienced trade member cannot tell, but it brings a 20 percent difference in price. Are we fair to the consumers? Perhaps we should leave such subjective grading systems behind us. At the minimum our OE cut is proven scientifically to give the ultimate brilliancy," contends Kawabuchi.

The launch of the OE cut was announced just a few weeks ago. How to manufacture them, where to manufacturer them and how to market them are still being studied, confesses Kawabuchi.

As it appears that it will be some time before OE cuts will be mass-marketed, Kawabuchi hopes that the OE cut will be accepted for what it is, as if it is a new cut in the family of fancy shapes.
Comment Comment Email Email Print Print Facebook Facebook Twitter Twitter Share Share
Tags: Consumers, Japan, Jewelry, Labs
Similar Articles
Kay Signet 150 120517Signet Facing Probe over Credit Practices
Dec 06, 2017
US authorities are investigating Signet Jewelers over its credit operations, the retailer revealed in a Securities and
© Copyright 1978-2017 by Martin Rapaport. All rights reserved. Index®, RapNet®, Rapaport®, PriceGrid™, Diamonds.Net™, and JNS®; are TradeMarks of Martin Rapaport.
While the information presented is from sources we believe reliable, we do not guarantee the accuracy or validity of any information presented by Rapaport or the views expressed by users of our internet service.