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In North America, isolated discoveries of diamonds at surface were reported
during the first half of the 19th century, and in September 1991,
the first kimberlite was discovered in the Lac de Gras area in the
Northwest Territories.
This topic explains the formation of diamonds and the exploration methods used to trace diamond sources. It also gives the history of diamond exploration and information on the first diamond mine opened in Canada.
Historical Facts
- 1863: A Diamond was found in glacial debris in Ontario.
- 1920: A 33-carat diamond was found during the construction of
a railway track, near Peterborough, Ontario.
- 1960's: Discovery
of small diamonds was reported east of Prince Albert, Saskatchewan.
- 1971: A 0.25-carat
gem quality diamond was discovered in the glaciofluvial sediment of
an esker, near Timmins, Ontario.
- 1981: Diamond
indicator minerals were found near the Mackenzie Range at the Yukon/Northwest
Territories border.
- September 1989:
Diamond exploration efforts intensified in the Northwest Territories.
Very high concentrations of diamond indicator minerals were found in
the Lac de Gras area, which suggested the location of a diamondiferous
kimberlite pipe.
- Following this
discovery, an unprecendented surge in exploration for diamonds happened
in Canada. For the first time, major diamond exploration companies faced
competition from a number of small, but technically proficient, exploration
companies.
- October 14th 1998:
BHP Diamonds Inc./Dia Met Minerals Ltd. announced the official opening
of Canada's first diamond mine: the Ekati Diamond Mine, Lac de Gras
area, in the Northwest Territories.
Question:
From the first diamond discovery in Canada to the opening of the first
diamond mine, why did so much time pass?
Answer
- Most kimberlites are well hidden under a thick blanket of glacial
material or under lakes.
- The occurrence
of several glacier advances that moved the eroded sediments in several
different directions, independently of the landscape.
- The complicated
ice flow routes make mineral indicators difficult to trace.
- Time needed for
the development of new techniques and technologies, such as heavy mineral
processing, petrology, geophysics, etc.
- Difficulties in
finding and putting together a team with all the different expertise
needed to perform all the necessary analysis.
- Time needed to
sample the terrain: Canada is a very large country.
- Time needed to
perform all the series of studies and analyses.
- Difficulties in
finding money needed to finance such exploration.
- Requirement to
perform several environmental studies and negotiate agreements with
all stakeholders involved.
All these factors
were obstacles, the quick realization of a project such as the exploitation
of a diamond mine in Canada.
Properties and Usefulness of Diamonds
Diamond is a mineral composed of carbon. Its dense crystal structure
makes diamond the hardest substance known. Diamonds are completely
transparent to a broad segment of the electromagnetic spectrum,
which makes them useful in industrial, technological and scientific
applications. Diamonds are also nonmetallic, do not conduct electricity
and have a great thermal conductivity.
Diamonds are not only used in the jewelry industry, but are present in
many technologies. Diamonds are used for machining plastic, glass and
metal pieces necessary in products such as laser printer drums, polygon
mirrors, automobile engine pistons, telephone, television, computers,
CD players, etc.
Diamonds can be made into ultra-hard and smooth cutting knifes and scalpels
for extremely precise surgery. Their resistance to wear becomes
an asset in automated processes that need to make large number of
copies of a same product, without having to replace the cutting
tool. Diamonds are also part of dental drills. Their hardness also
makes them useful as abrasive and grinding material.
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Diamonds, the hardest of all minerals, are not only used in the jewelry industry, but are present in many technologies which need resistant smooth-cutting tools. Diamonds form at a depth greater than 150 kilometres within the earth in distinctive parent rocks called kimberlites. Kimberlites also include several characteristic minerals that are very important as indicators in diamond exploration activities.