Geology: Papua New Guinea (PNG) lies at the northern end of the Australian Plate and has three major components: a continental cratonic platform, an arc of volcanic islands and a central collisional fold belt, consisting of mesozoic sediments, ophiolite sequences, tertiary sediments and diorite intrusions. During collision, the Wau Graben, the host of major gold and silver deposits, was formed in the fold belt. It coincided with a phase of volcanic activity, resulting in precious and base metal deposits being formed. These include epithermal gold deposits at Hidden Valley, Hamata, Kerimenge and Wafi and porphyry-style copper deposits such as Golpu. Numerous other gold and copper-gold prospects, which are at various stages of exploration and evaluation, occur on Harmony’s lease areas.

Note: Mineral resources and mineral reserves detailed in the following tables represent Harmony Newcrest Joint Venture 100% portion.

Gold – Mineral resources

Modifying factors

Operations	MCF (%)		PRF (%)
Hidden Valley	100		89
Hamata	100		89
Golpu	100		56

Gold – Mineral reserves

Silver as gold equivalent oz*

	Measured		Indicated		Inferred		Total
Operations	(000oz)		(000oz)		(000oz)		(000oz)
Hidden Valley	87		1 062		144		1 293
Grand total	87		1 062		144		1 293

Modifying factors

Operations	MCF   (%)		PRF   (%)
Hidden Valley	100		88

Silver – Mineral reserves

Silver as gold equivalent oz*

	Proved		Probable		Total
Operations	(000oz)		(000oz)		(000oz)
Hidden Valley	80		714		794
Grand total	80		714		794

* Gold equivalent is calculated using a pricing of US$1 150/oz (gold) and $13.50/oz (silver).

Copper – Mineral resources

Copper as gold equivalent oz*

	Measured		Indicated		Inferred		Total
Operations	(000oz)		(000oz)		(000oz)		(000oz)
Wafi-Golpu Project	–		36 604		6 712		43 316
Grand total	–		36 604		6 712		43 316

Modifying factors

Operations	MCF   (%)		PRF   (%)
Golpu	100		88

Copper – Mineral reserves

Copper as gold equivalent oz*

	Proved		Probable		Total
Operations	(000oz)		(000oz)		(000oz)
Wafi-Golpu Project	–		3 732		3 732
Grand total	–		3 732		3 732

* Gold equivalent is calculated using a pricing of US$1 150/oz (gold) and $2.50/lb (copper).

Molybdenum – Mineral resources

Modifying factors

Operations	MCF   (%)		PRF   (%)
Golpu	100		36

Molybdenum – Mineral reserves

Total mineral resources gold and equivalent oz

	Measured		Indicated		Inferred		Total
Operations	(000oz)		(000oz)		(000oz)		(000oz)
Gold	454		24 770		7 344		32 568
Silver	87		1 062		144		1 293
Copper	–		36 604		6 712		43 316
Grand total	541		62 436		14 200		77 177

Total mineral reserves gold and equivalent oz

	Proved		Probable		Total
Operations	(000oz)		(000oz)		(000oz)
Gold	422		4 530		4 952
Silver	80		714		794
Copper	–		3 732		3 732
Grand total	502		8 976		9 478

Reporting code
Harmony uses the South African Code for the Reporting of Exploration Results, Mineral Resources and Mineral Reserves (SAMREC code), which sets out the internationally recognised procedures and standards for reporting mineral resources and ore/mineral reserves in South Africa. This code was developed by the South African Institute of Mining and Metallurgy and is the recommended guideline for reserve and resource reporting for companies listed on the JSE Limited. Harmony’s reporting of its Australian and PNG mineral resources and mineral reserves also complies with the Australian Code for the Reporting of Mineral Resources and Mineral Reserves (JORC code) of the Australian Institute of Mining and Metallurgy. This code is materially the same as the SAMREC code. In reporting reserves, distinct cognisance has also been taken of Industry Guide 7 of the United States Securities Exchange Commission.

Mineral resources
A mineral resource is a concentration (or occurrence) of material of economic interest in or on the earth’s crust in such form, quality and quantity that there are reasonable and realistic prospects for eventual economic extraction. The location, quantity, grade, continuity and other geological characteristics of a mineral resource are known, estimated from specific geological evidence and knowledge, or interpreted from a well constrained and portrayed geological model.

Mineral resources are sub-divided in order of increasing confidence in respect of geoscientific evidence into inferred, indicated and measured categories.

An inferred mineral resource is that part of a mineral resource for which tonnage, grade and mineral content can be estimated with a low level of confidence. It is inferred from geological evidence and sampling, and assumed but not verified geologically and/or through analysis of grade continuity. It is based on information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes that may be limited or of uncertain quality and reliability.

An indicated mineral resource is that part of a mineral resource for which tonnage, densities, shape, physical characteristics, grade and mineral content can be estimated with a reasonable level of confidence. It is based on exploration, sampling and the testing of information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes. The locations are too widely or inappropriately spaced to confirm geological and/or grade continuity but are spaced closely enough for continuity to be assumed.

A measured mineral resource is that part of a mineral resource for which tonnage, densities, shape, physical characteristics, grade and mineral content can be estimated with a high level of confidence. It is based on detailed and reliable exploration, sampling and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes. The locations are spaced closely enough to confirm geological and grade continuity.

Mineral reserves
A mineral reserve is the economically mineable material derived from a measured and/or indicated mineral resource. It includes diluting and contaminating materials and allows for losses that are expected to occur when the material is mined. Appropriate assessments to a minimum of a pre-feasibility study for a project, or a life-of-mine plan for an operation, must have been carried out, including consideration of, and modification by, realistically assumed mining, metallurgical, economic, marketing, legal, environmental, social and governmental factors (the modifying factors). Such modifying factors must be disclosed.

A probable mineral reserve is the economically mineable material derived from a measured and/or indicated mineral resource. It is estimated with a lower level of confidence than a proved mineral reserve. It includes diluting and contaminating materials and allows for losses that are expected to occur when the material is mined. Appropriate assessments to a minimum of a pre-feasibility study for a project, or a life-of-mine plan for an operation, must have been carried out, including consideration of, and modification by, realistically assumed mining, metallurgical, economic, marketing, legal, environmental social and governmental factors. Such modifying factors must be disclosed.

A proved mineral reserve is the economically mineable material derived from a measured mineral resource. It is estimated with a high level of confidence. It includes diluting and contaminating materials and allows for losses that are expected to occur when the material is mined. Appropriate assessments to a minimum of a pre-feasibility study for a project, or a life-of-mine plan for an operation, must have been carried out, including consideration of, and modification by, realistically assumed mining, metallurgical, economic, marketing, legal, environmental, social and governmental factors. Such modifying factors must be disclosed.

To meet the requirements of the SAMREC code that the material reported as a mineral resource should have “reasonable and realistic prospects for eventual economic extraction”, Harmony has determined an appropriate cut-off grade which has been applied to the quantified mineralised body according to a process incorporating a long-term view on future economic modifying factors. In applying this process, Harmony uses a gold price of R390 000/kg to derive a cut-off grade to determine the mineral resources at each of its South African underground operations. Mineral resources have been estimated on the basis of geoscientific knowledge with input from the company’s mineral reserve managers, geologists and geostatistical staff. Each mine’s mineral resources are categorised, blocked-out and ascribed an estimated value. At all our mines computerised geostatistical estimation processes are used.

To define that portion of a measured and indicated mineral resource that can be converted to a proved and probable mineral reserve, Harmony applies the concept of a cut-off grade. At our underground South African mines, this is done by defining the optimal cut-off as the lowest grade at which an orebody can be mined such that the total profits, under a specified set of mining parameters, are maximised. The cut-off grade is determined using the company’s Optimiser software which requires the following as input: the database of measured and indicated resource blocks (per shaft section); an assumed gold price which, for this mineral reserve statement, was taken as R280 000/kg; planned production rates; the mine recovery factor (MRF) which is equivalent to the mine call factor (MCF) multiplied by the plant recovery factor (PRF); and planned cash operating costs (rand per tonne). Rand per tonne cash operating costs are historically based but take cognisance of distinct changes in the cost environment such as restructuring, right-sizing, and other cost-reduction initiatives, and for below-infrastructure ounces, an estimate of capital expenditure.

The block cave reserve at Golpu in PNG uses PCBC software to define the optimal mine plan and sequencing. The open-pit reserve at Hidden Valley in PNG is constrained by the capacity of the tailings storage facility with the Whittle optimisation programme guiding the most efficient mine design given this constraint.

The mineral reserves represent that portion of the measured and indicated resources above cut-off in the life-of-mine plan and have been estimated after consideration of the factors affecting extraction, including mining, metallurgical, economic, marketing, legal, environmental, social, and governmental factors.

A range of disciplines, including geology, survey, planning, mining engineering, rock engineering, metallurgy, financial management, human resources management and environmental management, has been involved at each mine in the life-of-mine planning process and the conversion of resources into reserves.

The modifying factors related to the oreflow that are used to convert the mineral resources to mineral reserves through the life-of-mine planning process are stated for each shaft. For these factors, historical information is used, except if there is a valid reason to do otherwise. As a result of the depth at which mining occurs and the resulting rock engineering requirements at our South African underground mines, some shafts include stope support pillars into the design of their mining layouts which accounts for discounts of 7% to 10%. A further 15% discount is applied as a life-of-mine factor to provide for unpay and off-reef mining. In general, life-of-mine plan extraction factors do not exceed 85% and are reflected in the mineral reserves.