Second Edition

U.S. DEPARTMENT OF THE INTERIOR

As the Nation's principal conservation agency, the Department of the Interior has responsibility for most of our nationally owned public lands and natural resources. This includes fostering the sound use of our land and water resources; protecting our fish, wildlife, and biological diversity; preserving the environmental and cultural values of our national parks and historical places; and providing for the enjoyment of life through outdoor recreation. The Department assesses our energy and mineral resources and works to assure that their development is in the best interests of all our people by encouraging stewardship and citizen participation in their care. The Department also has a major responsibility for American Indian reservation communities and for people who live in island territories under U.S. administration.

U.S. DEPARTMENT OF THE INTERIOR
Bruce Babbitt, Secretary

U.S. BUREAU OF MINES
Rhea Lydia Graham, Director

To develop a modern mining dictionary, the U.S. Bureau of Mines initiated a collaborative project with the American Geological Institute. The Bureau's staff, the Institute's staff and members, and many minerals experts throughout the Nation contributed their expertise to this work. In the 5-year project's final phase, more than 100 Bureau personnel were involved in the technical review and publication production process. I would like to thank all those who assisted in producing this new mining dictionary, especially the Dictionary Revision Group members and the Bureau's engineers, scientists, and editors.

The CD-ROM version of the Dictionary Revision is one of the last publications of the U.S. Bureau of Mines. Although the agency is closing, the Bureau's minerals information functions will transfer to the U.S. Geological Survey.

I believe this new dictionary will benefit the Nation by continuing one of the Bureau of Mines important missions, that of providing information on minerals, the building blocks of our modern society, and mining, one of the world's oldest industries.

Rhea Lydia Graham
Director
January 1996

The Bureau's development of mining dictionaries dates back to Albert Fay's Glossary of the Mining and Mineral Industry, which first appeared in December 1918. That glossary contained about 18,000 terms. In 1968, the Bureau published A Dictionary of Mining, Mineral, and Related Terms, edited by Paul W. Thrush, with about 55,000 terms. The 1968 dictionary contained many new mining terms and terms from such related areas as metallurgy, ceramics, and glassmaking. That edition was as complete as possible with regard to technical and regional terms, historical terms, foreign terms that attained general usage in the United States, and terminology from the entire English-speaking world. For the past three decades that work has stood as the definitive authority on mineral-related terms.

The 1996 edition reflects a departure from the previous one in scope and in format. This edition, containing some 28,500 terms, is not meant to be exhaustive in its coverage. It focuses on mining-related terms and excludes such related categories as ceramics, glass, metallurgy, petroleum, and other specialized disciplines. Geological terms which relate to mining are included, as are minerals which have a commercial value or which are associated with such minerals. Many chemicals and materials that are not usually connected with mining or minerals processing do not appear, nor do the chemical elements unless they are classified as minerals. Abbreviations and acronyms have largely been excluded, because they usually are explained and defined within the context of an individual report. The front material, however, includes a list of abbreviations used in the definitions. New terms on marine mining, leaching, and automation appear in this edition as do a plethora of pollution and environmental terms, many of which have a legal definition based on law or regulation.

The task of deciding which terms should be deleted from this edition, how to ensure the collection of new terms since 1968, and how to cull terms for inclusion was formidable. Terms from the 1968 edition were categorized by computer, and each category was reviewed by at least one subject specialist. The reviewers judged which terms should be retained or deleted, and they revised definitions as necessary and defined new terms. Final judgment on the inclusion of existing terms or the addition of new ones was left to the collective discretion of a panel of experts called the Dictionary Review Group. This group also examined the Society of Mining Engineers' Mining Engineering Handbook, 1993 edition, to ensure that the most modern terms and their definitions would be considered.

Two types of compound unit abbreviations are common.

1. In the metric system, many units comprise a basic unit, such as "m" (meter) modified by a prefix that acts as a "power of ten" multiplier. Thus "cm" is a "centi" "meter", one-hundredth of a meter or 10² meter.

Several compound metric units are widely used in this volume:

2. Complex units are developed by multiplying or dividing units. The metric units for momentum, for example, are kg-m/s, which is read Newton meters per second.