the lowest grade value that is included in a resource statement. It must comply with JORC requirement 19: "reasonable prospects for eventual economic extraction" the lowest grade, or quality, of mineralised material that qualifies as economically mineable and available in a given deposit. It may be defined on the basis of economic evaluation, or on physical or chemical attributes that define an acceptable product specification
formed from hydrothermal solutions within about one kilometre of the Earth's surface in the range of 50-200 °C. Typically found in volcanic rocks; chief metals are gold, silver, copper, lead and zinc
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 testing 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
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 assumed but not verified geological and/or grade continuity. It is based on information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes which may be limited or of uncertain quality and reliability
the Australasian Joint Ore Reserves Committee Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves, 2004 (the "JORC Code" or "the Code"). The Code sets out minimum standards, recommendations and guidelines for Public Reporting in Australasia of Exploration Results, Mineral Resources and Ore Reserves
a concentration or occurrence of material of intrinsic economic interest in or on the Earth's crust in such form, quality and quantity that there are reasonable prospects for eventual economic extraction. The location, quantity, grade, geological characteristics and continuity of a Mineral Resource are known, estimated or interpreted from specific geological evidence and knowledge. Mineral Resources are sub-divided, in order of increasing geological confidence, into Inferred, Indicated and Measured categories when reporting under JORC
formed from hydrothermal solutions at depths of between 6,000 and 20,000 metres in the temperature range of 300-550 °C. Among the common ore minerals in these deposits are gold, pyrite, chalcopyrite and galena
a regional metamorphic rock derived from clay-rich sedimentary rocks. Characterized by lustrous, often undulating, well-developed cleavage surfaces, often light silvery-grey in colour
an igneous rock in which relatively large crystals (phenocrysts) constitute 25% or more of the volume and are set in a fine-grained ground mass. Can also be used in conjunction with a mineral/metal name where the rock is rich in that component, e.g. quartz-feldspar porphyry
a white or colourless crystalline compound, SiO2, occurring abundantly as quartz, sand, flint, agate, and many other minerals and used to manufacture a wide variety of materials, especially glass and concrete