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Wedge-shaped stone at the crown of an arch.
Small crushed stone used as filler for the large aggregate in bituminous bound roads.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.


The central stone or voissoir at the top of the arch, the last part to be put into position to lock the arch in place, often embellished.
Illustrated Dictionary of Architecture Copyright © 2012, 2002, 1998 by The McGraw-Hill Companies, Inc. All rights reserved
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



in architecture, the stone or brick, usually wedge-shaped, at the top of an arch or vault. Its function is usually accentuated by ornamental patterns and carvings. A decorative keystone often adorns the flat lintel over the apertures of doors or windows. [9–963–l]

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

keystone, key block

keystone, 1: K
1. The central voussoir of an arch, which is often embellished; until the keystone is in place, no true arch action takes
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.
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By joining Keystone Property Group's established network of investment and real estate professionals, members are given support through clear lines of communication and have an open environment for discussion, sharing ideas, and passing on information.Full marketing material is provided to agents, alongside full training and support, while incentive bonuses are available for volume sales.
Keystone is for people who believe that powerful partnerships generate prosperity.
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Further, NWH's alleged misappropriation of Keystone's trade secrets has, according to Keystone, allowed NWH to take over Keystone's former operation and implement Keystone's unique business model without purchasing Keystone's business, arguably causing NWH's unjust enrichment and loss to Keystone.
The doubles leg went to Keystone 2-1 so they too had to endure a 1,001 match with all eight players taking part.With the teams evenly matched, both sides ended up with chances to finish before Keystone went through 4-3 to meet Railway Black Cats 2.
Keystone Bank is a technology and service-driven commercial bank offering convenient and reliable solutions to its customers.
The Next Steps For TransCanada After Trump's Keystone XL Order
Keystone has carved out a position in the colorant sector by combining strengths in custom formulation, product design and regulatory support for its diverse customer base.
Keystone is just one of many companies offering rates like this.
The proposed Keystone pipeline would be an oil pipeline system in Canada and the United States that would run oil from the Western Canadian Sedimentary Basin in Alberta to refineries in Illinois and Texas.
"Although (TransCanada has) been trying to keep the Keystone pipeline alive, really their attention is diverted onto other projects; there is more emphasis on Energy East and other elements," said Julie Brough, vice president at investment managers Morgan Meighen & Associates, which owns TransCanada stock.