February 2014
MODERN MINING
15
MINING News
Petra Diamonds recently recovered an
exceptional 29,6-carat blue diamond
(right) at the Cullinan mine near Pretoria.
According to the company, the stone is an
outstanding vivid blue with extraordinary
saturation, tone and clarity, and has the
potential to yield a polished stone of great
value and importance.
Blue diamonds are among the rarest and
most highly coveted of all diamonds and
the Cullinan mine is reportedly the most
important source of blues in the world.
This stone is one of the most exceptional
stones recovered at Cullinan during Petra’s
operation of the mine.
Cullinan earned its place in history with
the discovery of the Cullinan diamond in
1905, the largest rough gem diamond ever
found at 3 106 carats. This iconic stone was
cut into the two most important diamonds
which form part of the Crown Jewels in
the Tower of London – the
First Star of
Africa
, which is mounted at the top of the
Sovereign’s Sceptre and which at 530 carats
is the largest flawless cut diamond in the
world, and the
Second Star of Africa
, a 317-
carat polished diamond which forms the
centrepiece of the Imperial State Crown.
The mine is famous for large, high qual-
ity diamonds and has produced over 750
stones of greater than 100 carats and more
than a quarter of all the world’s diamonds
of greater than 400 carats.
“Exceptional”blue diamond
recovered at Cullinan
Since tak-
ing over the
mine in July
2008, Petra has
recovered several
world-class diamonds, including a 39-carat
blue diamond which sold for US$8,8 mil-
lion; a 26-carat blue diamond which Petra
cut into a 7-carat polished stone and sold
for US$9,4 million in 2009; a 507-carat
white diamond which Petra named the
Cullinan Heritage
and sold in 2010 for
US$35,3 million, this being the highest
price on record for a rough diamond; and
a 25,5-carat blue diamond that sold for
US$16,9 million in 2013.
Cullinan contains a world-class diamond
resource of 200,8 Mct (including 17,0 Mct
in tailings), and Petra is capitalising on this
by undertaking an expansion programme
at the mine to take annual production to
2,2 Mct by FY 2019 (comprising 2,0 Mct
ROM and 0,2 Mct tailings). This expansion
plan, known as C-Cut Phase 1, will estab-
lish a new block cave on the western side
of the orebody in the upper portion of the
major C-Cut resource (estimated to contain
some 133 Mct in total) and will also involve
a large tailings operation. Petra’s current
mine plan has a life of 17 years, but the
major residual resources at the mine indi-
cate that the actual LOM could be in excess
of 50 years.
Triton reports Balama North assay results
Australian company Triton Minerals, listed
on the ASX, has reported the assay results
from its initial two-hole diamond drill pro-
gramme at the Nicanda Hill prospect on
Licence 5966 at the Balama North project
in Mozambique.
These results confirm multiple zones
of high grade graphitic material over
significant widths, with mineralisation
intersections with grades up to 28,6 %
graphite being identified near to surface.
“These are tremendous initial drilling
results from the Nicanda Hill prospect,
confirming Triton’s belief in the overall
prospectivity of the Balama North proj-
ect,” says Triton’s Managing Director, Brad
Boyle. “These drilling results follow on
from the previously announced rock chip
sample results obtained from the Nicanda
Hill prospect, which identified high grade
large flake graphitic mineralisation, with
graphite flake sizes up to 1 mm, and
continue to support Triton’s belief that
the Balama North project has the poten-
tial to host multiple world class graphite
deposits.”
A more detailed exploration and drilling
programme is currently being designed to
further delineate the graphite mineralisa-
tion on the Nicanda Hill prospect. Triton
will start work on the primary part of this
highly promising target as soon as the wet
season ends, and it is able to complete the
necessary access roads.
