36 THENEWYORKER,FEBRUARY3, 2020
for copper and rare-earth metals near
Yellowknife, in Canada’s wild North-
west Territories. When Eira, his first
child, turned six, she began joining him
during her summer vacations. Gren
and his team had to be constantly on
the lookout to insure that little Eira
was not eaten by a bear. Like her fa-
ther, Eira was bright, curious, and out-
doorsy. In college, she abandoned a
plan to pursue medicine and got a ge-
ology degree instead. In 1991, when she
was twenty-two, Gren asked her to cut
short her post-graduation travels, in
Africa, to help him look for diamonds
in Canada.
Eira told her father, “Dad, there’s
no diamonds in Canada—everyone
knows that.”
I
n 1991, the industry was still domi-
nated by De Beers, which sold nearly
four billion dollars’ worth of rough di-
amonds that year—about eighty per
cent of the global supply. Most of that
“rough” originated in the company’s
own mines, in southern Africa. There
were also productive diamond mines
in Russia and Australia. Canada did
not feature on the diamantaire’s map
of the world.
However, for at least a decade there
had been promising signs that signifi-
cant diamond deposits might lie in the
far north of the country. Diamonds
were created billions of years ago, hun-
dreds of kilometres below the surface
of the earth, when carbon-bearing fluid
was formed into crystals under intense
heat and pressure. Over time, many of
the stones were brought to the surface
by subterranean volcanoes. The remains
of these eruptions took the form of kim-
berlite “pipes”—cylinders of diamond-
rich ore. Around Kimberley, South Af-
rica, such pipes became known as “blue
ground,” on account of their bluish
tinge, but in other countries kimber-
lite deposits are often a grayish green.
Finding evidence of a pipe is a good
start to finding a diamond. In the early
nineteen-eighties, several geologists,
including some from De Beers, dis-
covered “indicator minerals” suggest-
ing that such pipes existed in signifi-
cant numbers in Canada. Among the
minerals were lilac-colored, magne-
sium-rich garnets—stones, found in
soil and rivers, that were formed at
the same time as kimberlite, and that
indicate the presence of a pipe nearby.
In 1991, two geologists, Chuck Fipke
and Stu Blusson, used indicator chemis-
try to discover a pipe that later became
known as the Ekati mine, near Lac de
Gras, in the Slave Craton, an area about
two hundred miles northeast of Yel-
lowknife. It is a tough environment for
exploration; in winter, temperatures
regularly drop to minus thirty degrees
Fahrenheit. Nevertheless, the discovery
prompted a staking rush, with rival com-
panies claiming ground near Fipke and
Blusson’s site. By the end of 1991, Gren
Thomas’s small company, Aber, had
staked about a million acres of claims.
Other firms staked even more ground.
In the summer of 1992, Eira Thomas
travelled to the region with an explora-
tion team, taking along her northern
sled dog, Thor, which was part wolf, to
protect the group from bears. The ani-
mal was not as helpful as Thomas had
hoped: when a grizzly approached, the
dog whined for its owner. On another
occasion, Thor ran off, and was picked
up by a rival exploration team, sixty miles
away, whose members suspected that the
dog was part of a convoluted espionage
mission. The rivals sent Thor, by plane,
to Yellowknife, rather than allow Thomas
to retrieve the animal in person.
That summer, Aber and other min-
ing companies found evidence of sev-
eral kimberlite pipes. All of the pros-
pectors were looking for what is known
as an “economic” deposit: one rich
enough in diamonds to merit the vast
expense of mining in the desolate land-
scape of northern Canada. In the spring
of 1994, Eira Thomas returned to Lac
de Gras, as Aber’s chief geologist. She
was particularly interested in a prospect
that lay beneath the ice-covered lake.
Drilling vertically into the earth under-
neath a lake is problematic. In summer,
the ice that the drilling equipment rests
upon melts. Heavy rigs need to be moved
before they sink into the water.
At the time, Aber was in some finan-
cial trouble, and Gren Thomas was ne-
gotiating a merger with a larger firm.
Tests of the mineral chemistry of the
lake convinced Eira Thomas that a rich
deposit was buried beneath the water.
She and her team drilled for samples,
and the results were promising: the kind
of kimberlite that augurs a plentiful
supply of diamonds. But they hadn’t yet
identified an economic pipe.
By late May, 1994, the ice was start-
ing to melt. The drilling crew needed
to move their equipment off the lake.
But Thomas, seeking a sample of kim-
berlite from a prospect called A154
South, asked the miners to keep drill-
ing. They worked with water sloshing
up to their knees. On the last possible
day of drilling, the team retrieved a sam-
ple. A two-carat diamond was embed-
ded in one part of it. It’s almost un-
heard of to find an actual diamond
within a core—a tiny sample of the total
material in a pipe. As soon as Thomas
and the Aber team saw the glittering
stone, which was the size of an M&M,
they knew they’d struck pay dirt. That
night, Thomas slept with the diamond
under her pillow. She then flew to Van-
couver. When she met with her father,
she said nothing, and simply showed
him the sparkling rock in her hand.
“Is this for real?” Gren said.
T
he pipes that Eira Thomas discov-
ered became one of the world’s
richest diamond mines. By 2016, the
deposit, now known as Diavik, had pro-
duced more than a hundred million car-
ats. After the Thomases’ breakthrough,
other firms developed their own assets
in Canada. Within a decade, Canada
was producing sixteen per cent of the
world’s supply of gem-quality stones by
volume, and Eira was known as the
Queen of Diamonds. (Gren, who still
works in the business, and retains his
Welsh accent, says that he now asks
Eira for advice, rather than the other
way around.) The Canadian discover-
ies were part of a series of events in the
nineties that loosened De Beers’s stran-
glehold on the industry.
After that first success, Thomas and
McLeod-Seltzer, who met through a
mutual friend, formed a new company,
Stornoway, which went on to develop
Quebec’s first diamond mine, Renard.
But they longed to mine diamonds in
southern Africa—particularly in Bo-
tswana, a stable democracy where the
stones are plentiful and of high qual-
ity. Thomas recalls that Stornoway’s
mostly North American backers were
wary about investing, believing that
southern Africa was a high-risk area.
So, in 2007, she and McLeod-Seltzer
