Haggerty himself sports nary a studded cufflink nor pinky ring.
A pleasantly rumpled man with warm, deep-set eyes, he speaks in meticulous, staccato
rhythms as if reciting poetry. The lilt and cadence of his speech are informed by
both his native South Africa, where he was born 30 miles from the Premier diamond
mines, and long tenure in England. Haggerty could pass himself off as someone from
Auckland, Brisbane, Oxfordshire or Gander, which comes in handy in his frequent,
far-flung and often risky travels. A decorative or industrial diamond’s journey to
Zale’s, Tiffany, General Electric or Elizabeth Taylor’s ring finger often begins
in some of the world’s most inhospitable and acrimonious corners, and so Haggerty’s
science has found him stranded in a Monrovia hotel on the dawn of a violent 1980
civil war in Liberia, eating what he feared might be his last meal. He’s been subject
to harassment, suspicion and surveillance — not long ago he was patronized and misled
by the very same Syrian government agents who had invited him to their country. “Diamonds,”
he declares, “bring out the worst in people.”
Diamond deposits and working mines have lured Haggerty to the nether reaches of the
Siberian permafrost, where he celebrated the Fourth of July in a blizzard, and the
wilds of Brazil’s Amazon basin. He has worked in Mali, Senegal, Sierra Leone and
the Ivory Coast in west Africa and his expertise has taken him to China, Finland,
Iceland and southern India. He is at home in the bush, has logged untold miles in
the dusty confines of wheezing Land Rovers, and is known to don unconventional hats.
So it was only a matter of time before colleagues jokingly referred to Haggerty as
“the University’s Indiana Jones.” The nickname stuck, though mention of it seems
to embarrass Haggerty, who gives me a withering look and says, “oh, that.”
His global exploits notwithstanding, Haggerty in the flesh is nothing like the cartoonish,
swashbuckling Harrison Ford character. Well, yes, he did drag a sack of black diamonds
through the Liberian crossfire and pleaded with American embassy officials there
to grant the rocks temporary asylum. His countrymen were reluctant, but Haggerty
prevailed. (Getting the rocks home was the real ordeal.) But Haggerty describes himself
as a cautious man, scientist by occupation and adventurer by occupational hazard,
intent on getting the goods while keeping himself alive and in one piece. For another,
his exploits are played out in the company of sturdy graduate students and colleagues
rather than spies, roving opportunists or Kate Capshaw. Though he admits it is necessary,
on occasion, to bite his tongue and “dance with the devil” to be near the work he
loves, Haggerty is an outspoken supporter of human rights and follows developments
closely and hopefully in the regimes that have been his dancing partners. But Haggerty’s
most un-Hollywood attribute is his enthusiasm about his own backyard. Here is a man
who seems always to have just returned from some exotic tropical or sub-Saharan locale,
waxing poetic over a pre-Cambrian outcropping in Hadley. “People always ask me how
I feel about my travels,” says Haggerty. “And I tell them the best adventure is coming
home.”
I visit with Haggerty in his rustic Morrill laboratory, a space he wears like an
old sweater. What appears to the casual observer to be random piles of rubble are
samples with which Haggerty is so intimate he occasionally leaps out of his chair
and returns within seconds with a rock that precisely illustrates this or that geological
point, and he defers to the microscope as often as some men reach for their reading
glasses.
A native of South Africa’s high veldt who became an American citizen many years ago,
he is entranced by the geology of his adopted nation and particularly of western
Massachusetts. “At first I was worried I’d be academically isolated, that colleagues
wouldn’t want to travel here,” says Haggerty, who joined the faculty in 1971, after
a stint at the Geophysical Laboratory in Washington, D.C. “But that proved not to
be true — this area is a great natural laboratory and a rich playground for the geosciences,”
he says. That’s one reason Haggerty derives such pleasure from teaching a mineralogy
course for non-majors. He is intent on startling students into an appreciation of
the earth’s tempestuous history, and the ways in which its upheavals are chronicled
so candidly in the land before the students’ eyes.
Haggerty’s fascination with minerals found its first outlet when he was only 19 and
left Africa to work as an exploration assistant for a mining company in the wilds
of Canada’s James Bay. In Haggerty’s presence the use of “rock” or “stone” as a euphemism
for lifelessness seems profoundly inaccurate. Rocks are dynamic and packed with drama,
records of the earth’s eternal shifting, folding, cracking, exploding in hot lava
or being forever sculpted and transported by water and ice. They attest to an earth
on which Africa and South America formed a single land mass, an earth shaken and
rattled, boiled and cooled, frozen and thawed, even pelted with masses from outer
space.
When I ask Haggerty about his current research, he places a few raw specimens in
my hand. They are diamonds, sized at about 53 carats a piece. (A carat is a unit
of weight, with about 140 equaling an ounce.) But I never would have recognized them.
They are black diamonds and I could easily have mistaken them for worthless hunks
of gravel. Although they couldn’t be more ordinary looking, geologically speaking
these rocks couldn’t be more extraordinary, explains Haggerty, who has played a major
role in a scholarly debate over the black diamonds’ origin. There is nothing on the
planet remotely like them. Named carbonados by the Brazilians who first discovered
them in 1840, black diamonds are found almost exclusively in Brazil and the Central
African Republic, a country north of Zaire nestled between Chad and the Sudan.
Why the fascination with carbonados? They are exceedingly rare — only about two and
half metric tons of the rocks have been mined, usually from stream beds, since their
discovery. Like white diamonds they are the hardest minerals on earth and can only
be cut by other diamonds — it takes 6,000 pounds of pressure per square inch even
to dent one, says Haggerty, who managed (barely) to accomplish that much in his laboratory
after “seven days and seven nights” of effort. Carbonados were used in the Suez Canal’s
construction to break up other rocks. Unlike white diamonds, carbonados are porous
and agglutinated, meaning they’re comprised of clusters of crystals lurching every
which way as opposed to the near uniformity of their clear counterparts. As a result
they’ve got more cutting edges than other diamonds, and were used by the French in
the 19th century to carve and sand hardwood for furniture. The largest carbonado
ever found measures 3,167 carats, 60 times larger than the largest clear diamond.
Found in Brazil where it was named Sergio, the crystal weighs 1.4 pounds.
The rocks are a puzzle: scientists know what carbonados are but have only taunting
clues where they came from. Though they are as hard as white diamonds and, like those
diamonds, formed when ordinary carbon was subjected to immense heat and pressure,
carbonados appear to be significantly younger — about 3.2 versus 3.5 billion years.
Their estimated period of origin is out of sync with the volcanic evidence. The riddle
of the carbonado has long been the subject of debate, and explanations include a
theory that carbonados were born as the result of heat from natural radiation, the
impact of rocky asteroids or exploding stars. Still, says Haggerty, “no satisfactory
explan- ation exists for their origins. They may reveal a new geological source for
diamond forma- tion that hasn’t been recognized.”
Not long ago Haggerty fanned the flames of the carbonado debate when he put forth
a thoroughly original hypothesis — the carbonados of Africa and South America come
from the same meteorite or meteorites. Haggerty “stunned the experts,” the New York
Times reported, with his theory that billions of years ago dis- tant exploding stars
rich in carbon produced dense clumps of diamonds from the shock waves and pressure.
Car-bonados, he speculates, could be the resulting diamond aggregates, black diamond
boulders that entered our solar system and plummeted to earth, fragmenting in the
process. The idea of diamonds in meteorites isn’t new; it was first discovered a
decade ago that tiny diamonds can form that way. But after comparing values for carbon
isotopes’ radioactive decay in various ancient rocks and meteorite samples, Haggerty
began to suspect that carbonados come from a new class of “presolar” meteorites,
long-surviving fragments of which, sucked into our solar system by the sun’s gravitational
pull, eventually fell to earth through the oxygen-poor atmosphere of the pre-Cambrian
period.
“When you put all the pieces together,” says Haggerty — the apparent presence of
a certain type of weak chemical bond, the isotopic frequencies of long-decaying carbon
isotopes, and the rocks’ signs of intense heating and shock — it seems as if these
black diamonds formed 2.6 to 3.8 billions years ago. “Beginning about 4.5 billion
years ago the earth was pummeled by meteorites, and this lasted for 5 million years,”
he says. “We don’t see the scars they left because of erosion — the evidence was
destroyed on earth — but it is beautifully preserved on Mars and the moon. That’s
because those atmospheres are low in oxygen, which would turn the meteorite fragments
into immense fireballs. But nearly 4 billion years ago the earth’s atmosphere had
little or no oxygen, and so the black diamonds could have rained down unimpeded.”
So why would carbonados be found only in Brazil and central Africa? It Haggerty’s
right about the diamonds’ origin, they fell to earth before an ancient block of the
earth’s crust fractured into South American and Africa. ‘“Look,” he says, gesturing
to a world map over his desk. Immediately I see that the two continents fit together
like a jigsaw puzzle.
Not everyone is convinced. Haggerty’s model has been criticized because of the carbonados’
small size — what made the fragments splinter to such an extent? — and because some
isotopic data don’t jibe with Haggerty’s presolar profile of the rocks. Haggerty
doesn’t mind the naysayers, who serve, in the true spirit of scientific inquiry,
to fuel his enthusiasm. He is consumed by one goal “to produce a quantitative definition
of a carbo-nado.” “It’s kind of an inverse fascination,” he says, noting the irony
of these prosaic-looking rocks capturing his imagination after years spent in the
hypnotic glare of perfect white diamonds. “I’ve been fixated by these objects for
two years,” he says, turning a carbonado over in his hand. “They’re so nondescript,
and yet they have this incredibly rich history.”
Soon after our meeting Haggerty was off to Pretoria, South Africa. It was to be his
first visit since the days of apartheid, a policy of which Haggerty was deeply ashamed;
here was a devil with whom he refused to dance. Returning to Nelson Mandela’s South
Africa will be a happy homecoming for the ambitious boy from the high veldt who fell
in love with diamonds, which brought out the very best in him. |
|
