slate

slate

1. 

a. a compact fine-grained metamorphic rock formed by the effects of heat and pressure on shale. It can be split into thin layers along natural cleavage planes and is used as a roofing and paving material

b. (as modifier): a slate tile

2. a dark grey colour, often with a purplish or bluish tinge

3. Chiefly US and Canadian a list of candidates in an election

4. Films

a. the reference information written on a clapperboard

b. Informal the clapperboard itself

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

slate

A hard, brittle metamorphic rock characterized by good cleavage along parallel planes; used as cut stone in thin sheets for flooring, roofing, and panels, and in granular form as surfacing on composition roofing.

See also: Stone

Illustrated Dictionary of Architecture Copyright © 2012, 2002, 1998 by The McGraw-Hill Companies, Inc. All rights reserved

slate

[slāt]

(petrology)

A group name for various very-fine-grained rocks derived from mudstone, siltstone, and other clayey sediment as a result of low-degree regional metamorphism; characterized by perfect fissility or slaty cleavage which is a regular or perfect planar schistosity.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

slate

A hard, brittle metamorphic rock consisting mainly of clay minerals, characterized by good cleavage along parallel planes; used extensively as dimension stone in thin sheets for flooring, roofing, panels (both decorative and electrical), and chalkboard, and in granular form as surfacing on composition roofing.

McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.

slate

Another name for a tablet. In 2010, HP introduced tablets under the Slate brand. See Tablet PC and tablet.

Copyright © 1981-2025 by The Computer Language Company Inc. All Rights reserved. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction is strictly prohibited without permission from the publisher.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Slate

 

a schistous, sedimentary rock used for roofing. It consists of argillaceous minerals (for the most part, various hydromicas and chlorite) whose particles are usually arranged in strictly parallel lines. This structure gives slate a sharply defined schistosity, that is, the capacity for cleavage into thin lamina. Slate does not fall apart in water and has the characteristics of geosynclinal sediments. It is formed by the compaction of clays and their partial recrystallization under pressure at considerable depths as well as by the effect of dynamic metamorphism. When it undergoes further change, it becomes a phyllte or a chlorite slate.

The largest known deposits of slate in the USSR are located in the Caucasus and the Urals. Slate is used as roofing material; in the production of low-voltage switchboards, knife switches, and other apparatus in the electrical industry; and in the production of certain structural components (panels for the interior facing of rooms). Slate is also used in a crushed, roasted, and aerated form as filler for certain types of concrete, large wall blocks, and for cladding ruberoid(roof-sheeting material).

V. P. PETROV

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.