Diamonds:Gemology

EightStar diamonds are a study of the internal light path

Richard von Sternberg wants to throw away most mathematical formulas in the cut-grade business. Instead, he proclaims the virtues of non-mathematical cuts by his own firm, EightStar™ Diamond Co., Santa Rosa, CA.

The suggestion of expunging the venerable proportions Marcel Tolkowsky developed for what became known as the Ideal Cut may sound sacrilegious. But when you consider the polish, scintillation and balance of an EightStar diamond, his suggestion requires another look-see. Essentially, the EightStar diamonds are cut to make the most of each diamond's unique physiology.

"Close to half of all diamond crystals have enough internal aberration to polarize and redirect light," says von Sternberg. "A cutter who concentrates too much on mathematical formulas and a unidimensional exterior concept of symmetry will align facets in such a way that, due to polarization, light will not go to the facet opposite where it entered." This is why two diamonds cut to exact mathematical proportions may not have equal brilliance and scintillation.

Massaging the Numbers
It's true that in today's world not all Ideal Cut diamonds are cut to the exact formula Tolkowsky developed in 1919 (Professional Jeweler,August 1998, p. 40). Tables and other proportions vary, reflecting consumer tastes.

With EightStar diamonds, the table and depth percentages are well within Ideal proportions, says von Sternberg. What's flexible are the crown and pavilion angles. While careful not to divulge company trade secrets, he says the key is understanding how light travels in a diamond. "The most important view of a diamond is from the top," he says. "It's necessary to direct each mirror of the diamond so light goes exactly where it must to make the diamond maximally beautiful.

"This means each diamond must be considered individually – apart from any all-encompassing formula of Ideal proportioning – for stress and grain features and the phenomenon of light polarity." He compares it to two people holding mirrors standing on opposite sides of a gorge: "The idea is for each person to use the mirror to direct light into the opposite person's eyes."

In Store
EightStar diamonds, all of which are fashioned from previously cut diamonds, enter the market at the rate of about 2,000 per year worldwide. The low number can be attributed to the time it takes to recut them: 30-32 hours each.

EightStar diamonds cost about 20% more than diamonds cut to Ideal proportions. But their one-of-a-kind stature is well-suited to customers who enjoy precision-cut and unique gems.

The company recently unveiled a program designed to entice retailers. "When you buy diamonds from us, we give you a chance to take the same number of diamonds as you ordered out of your inventory and have us recut them for a nominal fee," he says. "This allows you to get rid of the 'dogs,' upgrade your inventory and average out the costs."

For a nominal fee, EightStar also provides a FireScope. Viewed through this tool, the diamonds show an eight-ray pattern thanks to their exacting alignment and light return.

EightStar Diamond Co., Santa Rosa, CA, (707) 575-4419, fax (707) 575-5841, e-mail eightstar@aol.com, www.eightstar.com.

The main pavilion facets of this 0.52-ct. EightStar diamond are perfectly aligned. Gem courtesy of EightStar Diamond Co.

An EightStar diamond viewed through a FireScope shows this pattern of facet reflections as well as the path of light (shown in red.) Image courtesy of EightStar Diamond Co.

– by Robert Weldon, G.G.

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