australia's identified mineral resources 2005 - Geoscience Australia

AUSTRALIA’S IDENTIFIED MINERAL RESOURCES 2005
Accessible EDR
All diamond EDR is accessible for mining.
JORC Reserves
JORC Code reserves account for almost all AEDR. The remaining AEDR comprise those measured
and indicated resources (reported by mining companies), which Geoscience Australia has assessed
as being economic in the long term.
Exploration
ABS data indicate that expenditure on exploration for diamond in Australia in 2004 was $25.4 million,
down 8% on 2003. Exploration continues to be concentrated in Western Australia, notably the
Kimberley region, Northern Territory and South Australia.
Abner Range (NT): Gravity Diamonds Ltd announced the discovery of a diamondiferous kimberlite
(ABN21) south of the McArthur River mine after drilling a Falcon® airborne gravity anomaly. Detailed
ground gravity surveys and geological mapping are being conducted to outline the potential shape
and size of the kimberlite body to enable more detailed test drilling and bulk sampling. A further 28
targets within 10 km radius of the ABN21 are to be mapped and sampled.
Seppelt (WA): Striker Resources NL continued exploration in the North Kimberley region at its
Seppelt project, which comprises a number of related kimberlite dykes, blows and pipes over a
strike length of some 6 km. At the Seppelt 2 pipe the largest diamonds recovered to date include
one 8.5 c and one 6.3 c diamond. The 8.5 c clear white diamond is of gem quality and valued at
US$1 500 per carat. The 2004 work program focused on assessing the viability of open-pit mining at
the high grade Seppelt 2 pipe (at 211 cpht for the weathered kimberlite), the Seppelt 1 pipe and the
Seppelt 5 fissure as well as assessing the potential for underground mining at Seppelt 5 and Seppelt
2. Following the sale of 5 618 carats at an average price of US$35/carat, largely from lower grade
infill gravels, trial mining at Seppelt 2 was discontinued in favour of further exploration in the region
and an immediate focus on advancing the Merlin Project.
Ellendale (WA): Kimberley Diamond Company Ltd discovered nine small pipes in 2004 (Kimberley
Pipes 33 to 41), all within trucking distance of existing infrastructure at Pipe 9.
Flinders Ranges (SA): Flinders Diamonds Ltd reported the discovery 11 kimberlites, mostly in
the Euralia region, three of which carry micro diamonds. Two small kimberlite pipes were also
discovered in the Angaston region in the Adelaide Hills following detailed airborne and ground
magnetic surveys and sampling.
Production
Australia produced 20.7 Mc of diamond in 2004, making it the world’s fourth largest producer of
diamond by weight after Botswana, Russia and Congo (Kinshasa). As a producer of gem/near gem
diamond, Australia is the fourth largest after Botswana, Russia and Canada and as producer of
industrial grade diamond Australia is the third largest.
30
Production was almost entirely from the Argyle mine (AK1 pipe), which produced 20.62 Mc,
mostly industrial and cheap diamonds with an average price of US$15–16. Production was down
substantially from the 30.91 Mc mined in 2003 as a consequence of difficult near-base-of-pit mining
conditions, which resulted in mining of lower grade ore. The average grade mined for the year was
2.15 cpt (cf 3.16 cpt in 2003).
Production from Kimberley Diamond’s Ellendale mine in the West Kimberley region increased to
82 039 c up from 57 000 c in the previous year. Production was from the Ellendale 9 pipe where
high-value fancy yellow gem diamonds (average sale price in 2004 US$258 per carat) were mined.