Norite Coarse-grained igneous rock composed of the minerals plagioclase feldspar and orthopyroxene.
Ore That part of a mineral deposit which could be economically and legally extracted or produced at the time of reserve determination.
Outcrop The part of a rock formation that appears at the earth’s surface often protruding above the surrounding ground.
PGM The platinum group metals collectively and in any combination of palladium, platinum, rhodium, ruthenium, osmium, and iridium. Reference to PGM grades for the Company’s operations include measured quantities of palladium and platinum only.
PGM rich matte Matte is an intermediate product of smelting; an impure metallic sulfide mixture made by melting sulfide ore concentrates. PGM rich matte is a matte with an elevated level of platinum group metals.
Probable Reserves for which quantity and grade and/or quality are computed from information similar (indicated) to that used for proven (measured) reserves, but the sites for inspection, sampling, and reserves measurement are farther apart or are otherwise less adequately spaced. The degree of assurance, although lower than that for proven (measured) reserves, is high enough to assume continuity between points of observation.
Proven (measured) Reserves for which (a) quantity is computed from dimensions revealed in outcrops, trenches, reserves workings or drill holes; grade and/or quality are computed from the results of detailed sampling; and (b) the sites for inspection, sampling and measurement are spaced so closely and the geologic character is so well defined that size, shape, depth and mineral content of reserves are well established.
Recovery The percentage of contained metal actually extracted from ore in the course of processing such ore.
Reef A layer precipitated within the Stillwater Layered Igneous Complex enriched in platinum group metal-bearing minerals, chalcopyrite, pyrrhotite, pentlandite, and other sulfide materials. The J-M Reef, which the Company mines, occurs at a regular stratigraphic position within the Stillwater Complex. Note: this use of “reef” is uncommon and originated in South Africa where it is used to describe the PGM-bearing Merensky, UG2, and other similar layers in the Bushveld Complex.
Refining The final stage of metal production in which residual impurities are removed from the metal.
Reserves That part of a mineral deposit which could be economically and legally extracted or produced at the time of the reserve determination.
Recycling materials Spent PGM-bearing materials collected for reprocessing from automotive, petroleum, chemical, medical, food and other catalysts. Additionally, PGMs for recycling may be sourced from scrap electronics and thermocouples, old jewelry and materials used in manufacturing glass.
Shaft A vertical or steeply inclined excavation for the purposes of opening and servicing an underground mine. It is usually equipped with a hoist at the top which lowers and raises a conveyance for handling personnel and materials.
Slag Slag is a nonmetallic product resulting from the mutual dissolution of flux and nonmetallic impurities during smelting. A silica rich slag is a smelting slag that contains a relatively high level of silica.
Sill (1) With respect to a mine opening, the base or floor of the excavated area (stope); (2) With respect to intrusive rock, a tabular intrusive unit that is conformable with surrounding rock layers.
4