A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

D

Day order       An order to buy or sell shares, good only on the day the order was entered.

Debenture       see Bonds.

Debt financing       Method of raising capital whereby companies borrow money from a lending institution.

Deck       The area around the shaft collar where men and materials enter the cage to be lowered underground

Decline       A sloping underground opening, usually driven at a grade of about 15% to 20%, for machine access from level to level or from surface; also called a ramp. An underground tunnel developed on a sloping grade for traveling around an underground mine in a self-propelled vehicle or mining machine. These tunnels are often driven in a spiral, much the same as a staircase, to access different elevations in the mine.

Deep Leed       A run of alluvial gravel's or a gold bearing alluvial seam that uses underground methods to extract it.

Deferred charges       Expenses incurred but not charged against the current year's operation.

Demonstrated reserves       A collective term for the sum of coal in both measured and indicated resources and reserves.

Depletion       An accounting device, used primarily in tax computations. It recognizes the consumption of an ore deposit, a mine's principal asset.

Deposit       Mineral deposit or ore deposit is used to designate a natural occurrence of a useful mineral, or an ore, in sufficient extent and degree of concentration to invite exploitation.

Depreciation       In accounting, the practice of deducting annually a specified amount or percentage from the value of equipment and machinery representative of the deterioration suffered by the equipment or machinery during the year. The deduction reduces the amount of profit reported but is not an actual out-of-pocket expense.

Detectors       Specialized chemical or electronic instruments used to detect mine gases.

Detonator       A device containing a small detonating charge that is used for detonating an explosive, including, but not limited to, blasting caps, exploders, electric detonators, and delay electric blasting caps.

Detonator House       A magazine used to store detonators.

Detritus       A general term covering all unconsolidated sediments.

Development       Underground work carried out for the purpose of opening up a mineral deposit. Includes shaft sinking, crosscutting, drifting and raising.

Development drilling       Drilling to establish accurate estimates of mineral reserves.

Development mining       Work undertaken to open up coal reserves as distinguished from the work of actual coal extraction.

Diabase       A common basic igneous rock usually occurring in dykes or sills.

Diamond       The hardest known mineral, composed of pure carbon; low-quality diamonds are used to make bits for diamond drilling in rock.