Bench
A ledge that, in open-pit mine and quarries, forms a single level of operation above which minerals or waste materials are excavated from a contiguous bank or bench face. The mineral or waste is removed in successive layers, each of which is a bench, several of which may be in operation simultaneously in different parts of, and at different elevations in, an open-pit mine or quarry.

Bio-oxidation
Bio-oxidation is a pre-treatment process, which oxidizes and removes sulfides that have encapsulated gold. The exposed gold is then leached using traditional methods, such as cyanide. This pre-treatment has improved gold recovery and has allows the development of previously uneconomical zones.

Blast hole
A hole drilled in a material to be blasted, for the purpose of containing an explosive charge.

Breccia
A coarse-grained rock composed of angular, broken rock fragments held together by a mineral cement or in a fine-grained matrix.

Carbon-in-leach
A gold recovery process in which a slurry of gold-bearing ore, carbon and cyanide are mixed together. The cyanide dissolves the gold, which is subsequently absorbed by and separated from the carbon.

Conversion factors
Weights and measures on this site represent units commonly used in the gold industry. Conversion factors are provided below:

To Convert Imperial Measurement Units		To Metric Measurement Units		Multiply By
Acres		Hectares		0.404686
Feet		Metres		0.30480
Miles		Kilometres		1.609344
Ounces (troy)		Grams		31.1035
Pounds		Kilograms		0.454
Short tons		Tonnes		0.907185
Troy ounces per ton		Grams per tonne		34.2857

Cut-off grade
The minimum metal grade at which a tonne of rock can be processed on an economic basis.

Deposit
A mineralized body which has been physically delineated by sufficient drilling, trenching and/or underground work and found to contain a sufficient average grade of metal or metals to warrant further exploration and/or development expenditures; such a deposit does not qualify as a commercially mineable ore body or as containing mineral reserves until final legal, technical and economic factors have been resolved.

Flowsheet
A diagram showing the progress of material through a preparation or treatment plant. It shows the crushing, screening, cleaning or refining processes to which the material is subjected from the run-of-mine state to the clean and sized products. The size range at the various stages may also be shown.

Electrowinning
An electrochemical process used to recover gold and other metals from solution in the leaching of ores and concentrates.

Grade
The amount of gold in each tonne of ore, usually expressed in grams per tonne.

Mineralization
The concentration of minerals within a body of rock

Ounce (troy)
All ounces referenced on this website are troy ounces. Despite the world's gradual conversion to the metric system, the troy ounce remains a fixture of the gold industry and the most important basis for expressing quotations of most gold markets. One troy ounce equals approximately 31.1 grams in weight. There are 32.15 troy ounces in a kilogram.

Reserves and Resources
Centerra's classification of mineral reserves and resources and the subcategories of each conforms with definitions adopted by the Canadian Institute of Mining, Metallurgy and Petroleum Council on August 20, 2000, which are in accordance with Canadian Securities Administrators' National Instrument 43-101 dated November 17, 2000.

Mineral resource A mineral resource is a concentration or occurrence of natural, solid, inorganic or fossilized organic material in or on the earth's crust in such form or quantity and of such a grade or quality that is has reasonable prospects for 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. Inferred mineral resource An inferred mineral resource is that part of a mineral resource for which quantity and grade or quality can be estimated on the basis of geological evidence and limited sampling and reasonably assumed but not verified, geological and grade continuity. The estimate is based on limited information and sampling gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes. Indicated mineral resource An indicated mineral resource is that part of a mineral resource for which quantity, grade or quality, density, shape, and physical characteristics can be estimated with a level of confidence sufficient to allow the appropriate application of technical and economic parameters, to support mine planning and evaluation of the economic viability of the deposit. The estimate is based on detailed and reliable exploration and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes that are spaced closely enough for geological and grade continuity to be reasonably assumed. Measured mineral resource A measured mineral resource is that part of a mineral resource for which quantity, grade or quality, density, shape and physical characteristics are so well established that they can be estimated with confidence sufficient to allow the appropriate application of technical and economic parameters, to support production planning and evaluation of the economic viability of the deposit. The estimate 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 that are spaced closely enough to confirm both geological and grade continuity. Mineral reserve A mineral reserve is the economically mineable part of a measured or indicated mineral resource demonstrated by at least a preliminary feasibility study. This study must include adequate information on mining, processing, metallurgical, economic and other relevant factors that demonstrate, at the time of reporting, that economic extraction can be justified. A mineral reserve includes diluting materials and allowances for losses that may occur when the material is mined. Probable mineral reserve A probable mineral reserve is the economically mineable part of an indicated, and in some circumstances a measured mineral resource, demonstrated by at least a preliminary feasibility study. This study must include adequate information on mining, processing, metallurgical, economic and other relevant factors that demonstrate, at the time of reporting, that economic extraction can be justified. Proven mineral reserve A proven mineral reserve is the economically mineable part of a measured mineral resource demonstrated by at least a preliminary feasibility study. This study must include adequate information on mining, processing, metallurgical, economic and other relevant factors that demonstrate, at the time of reporting, that economic extraction is justified.

Reclamation
The process by which lands disturbed as a result of mining activity are reclaimed back to a beneficial land use. Reclamation activity includes the removal of buildings, equipment, machinery and other physical remnants of mining, closure of tailings impoundments, leach pads and other mine features and contouring, covering and re-vegetation of waste rock piles and other disturbed areas.

Refractory Ore
Mineralized rock in which much of the gold is encapsulated in sulphides or other minerals and is not readily amenable to dissolution by cyanide solutions (unlike oxidized ore) even with fine grinding.

Strip ratio
This is the ratio between the volume of total waste material and the volume of gold bearing ore at the mine site.

Tailings
The material that remains after all economically recoverable metals or minerals of economic interest has been removed from the ore through milling and processing.

Ton
A ton or short ton is a British imperial measure of weight equivalent to 2,000 pounds.

Tonne
A tonne or metric tonne is about 10% greater in weight than a short ton and equivalent in weight to 1000 kilograms or 2,205 pounds.

Waste
Barren rock in a mine, or mineralized material that is too low in grade to be mined and milled at a profit.