Background info, great for newbies, fills gaps for the rest of us.
Published Sunday, February 6, 2000
Diamond too pricy to truly shine
The high cost of the multifaceted substance
has, for the most part, buried its practical uses
By Guy Gugliotta
WASHINGTON POST
Marilyn Monroe may have insisted that "diamonds are a girl's best
friend," but scientists today would like to enlarge the circle of
admirers by making diamonds the servant of everyman.
Besides its traditional role as the world's finest bauble, diamond is
also the world's finest abrasive, finest semiconductor, finest
insulator, finest refractor of light and finest thermal conductor.
A synthetic diamond wafer can slice an ice cube in half in a
couple of seconds using the heat from a single human hand.
But aside from creating an $800 million-per-year abrasives
industry, the diamond has never fulfilled its promise.
Forty-five years after scientists first synthesized it, the diamond
continues to confound efforts to put its unsurpassed virtues to
more practical use.
"It was going to be the answer to everybody's prayer," said Donald
Knight, a specialist in finding practical uses for technology
developed at the Argonne National Laboratory in Argonne, Ill.
"But it's expensive and hard to work with, and people can always
find a solution somewhere else."
Although scientists for decades have focused on making diamond
into a workaday product, recent events suggest that industry may
have found more profitability by moving up-market.
General Electric Co., the inventor of synthetic diamond, recently
began test-marketing natural stones that have been
color-enhanced with a new high-pressure process.
"Market research has shown improved buyer interest with zero to
minor discounts," said Bill Woodburn, vice president and general
manager of GE's super abrasives division.
"I emphasize 'minor.' A deeply discounted diamond is viewed as
flawed, and these diamonds are gorgeous."
And this month, Novatek Inc., a Provo, Utah-based company
founded by one of the GE researchers who developed synthetic
diamond, will begin online sales of fancy green and yellow-green
"NovaDiamonds" made by squeezing lower-value colored stones
at a pressure of 1 million atmospheres and temperatures
approaching 3,600 degrees Fahrenheit.
If the public embraces the new products, economics will do the
rest. The value of an off-color diamond can in some cases be
nearly doubled by altering its crystal structure slightly to whiten it
with GE's high-pressure process.
And in Provo, Novatek President David Hall is buying raw natural
stones for hundreds of dollars per carat and transforming them
into reasonably priced green diamonds, a type of stone so rare
that it is virtually unavailable to the general public today.
"This is the Holy Grail" of the diamond business, Hall said.
If it sells. For, as experts are careful to point out, a diamond is,
above all, unpredictable.
An unmounted, flaw-free, one-carat (.007 ounce) white stone can
be worth $5,000 to $10,000. A one-carat Lucida diamond ring from
Tiffany can retail for as much as $18,000.
But "people want the natural stones," said Robert M. Hazen, a
mineralogist at the Carnegie Institution of Washington and the
author of a history of synthetic diamonds.
"The idea is that if it's been around a long time, it will be around a
long time. If you made it in your basement last week, people don't
want to hear it."
Diamond is crystalline carbon, created deep in the Earth under
tremendous heat and pressure and exploded to the surface,
where it is mined in "diamond pipes" or recovered in alluvial
deposits.
Diamond was revered in ancient India, but throughout this century
the industry has been centered in South Africa, with significant
numbers of stones coming from several other African countries,
India, Russia, Australia, Brazil, Venezuela and, most recently,
Canada.
World sales of gem diamonds are managed by the De Beers
Central Selling Organization, the commercial arm of the Kimberly,
South Africa-based company that controls 50 percent to 80
percent of the diamond trade.
In 1997, the last year for which statistics are available, about $12
billion in gem diamonds were sold around the world, the vast
majority in the one- to five-carat range.
"That's where the money is," said George E. Harlow, curator of
minerals and gems at the American Museum of Natural History in
New York. "The big stones is where the hoopla is."
The synthesis of diamond was motivated primarily by a desire to
find a reliable Cold War source of abrasives for oil drilling bits,
quarrying saws and other heavy-duty cutting tools.
Diamond is both the world's hardest known substance and its
best thermal conductor, making it ideal for jobs requiring durability
without overheating.
Over the years, advances in high-temperature and high-pressure
synthesis have enabled industry to create diamond grit or dust in
shapes and sizes to order.
Novatek makes high-quality polycrystalline inserts for drill bits by
fusing synthetic diamond around metal additives. Woodburn said
GE makes 6,000 kinds of diamond abrasives.
For the past 20 years, however, research has focused on
low-pressure synthesis, in which hydrocarbons in a vacuum
chamber are "cracked" in the presence of hydrogen in a
high-temperature microwave field, causing a thin film of diamond
to form.
"All hell broke loose," said Pennsylvania State University's
Rustum Roy, one of the world's leading low-pressure synthesis
researchers.
It suddenly seemed possible to make diamond microchips,
diamond sheets for heat dispersal and diamond coatings so
strong that knives would never dull and eyeglasses would never
scratch.
So far, however, results have been modest. Low-pressure
synthesis is too slow to be economically viable except in narrow
product niches. Diamond films don't adhere to steel and are too
expensive for eyeglasses.
In a recent paper in the journal Nature, Belgian researcher Jean
Charlier reported synthesizing 10 to 100 micrometers of diamond
by vaporizing graphite in a vacuum with a 10-millisecond burst of
heat, a far faster rate of growth -- and potentially cheaper -- than
any other low-pressure method.
But Charlier said he does not know how cheap the process could
be, or if his method can work beyond a single event.
Microcircuitry research, meanwhile, is all but "moribund," Roy
said, because scientists cannot appropriately "dope" diamond --
salt the film with impurities so that electricity can be conducted.
In optics, scientists have created small diamond "windows,"
useful in rocketry or other applications requiring high transparency
and high resistance to heat and radiation.
Again, however, "it's godawful expensive," Roy said, and only the
government can afford it.
And in Northborough, Mass., Norton Diamond Film produces
diamond disks for heat dispersal mounts for microelectronics.
As chips get smaller and are grouped closer together, the need
for effective heat transfer grows, and Tom Colyer, Norton's general
manager, thinks the use of diamonds is an answer.
"We are just starting to make money," he said.
In all the new applications, however, money is the main drawback.
"Some say diamond is a good way to make a $200 part out of a
$10 part," said Argonne's Knight, and diamond will probably
remain a bystander until the math improves.
PHIL |
