Periclase


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periclase

[′per·ə‚klās]
(mineralogy)
MgO Native magnesia; a mineral occurring in granular forms or isometric crystals, with hardness of 6 on Mohs scale, and specific gravity of 3.67-3.90. Also known as periclasite.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Periclase

 

a mineral that consists of natural magnesium oxide (MgO) with occasional admixtures of FeO, MnO, and ZnO. Periclase, whose crystal structure resembles that of rock salt, crystallizes in the isometric system to form cubic and octahedral crystals as well as irregular grains; cleavage is perfect along the cube. Periclase is grayish white, yellow, dark green, or black with a hardness of 5.5–6 on Mohs’ scale and a density that ranges from 3,600 to 3,900 kg/m3. It is characteristic of meta-morphic limestones and dolomites. As a result of weathering, periclase alters to brucite and hydromagnesite. Artificial periclase, which is usually prepared by sintering natural magnesite at 1600”-1650oC or by electrically smelting natural magnesite, is important in manufacturing magnesite refractories.

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

periclase

A crystalline mineral which is sometimes found in portland cement, portland cement clinker, and certain slags.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.
References in periodicals archive ?
Previous calculations of the linear absorption coefficients for the cement phases and that of a mixture from certification of the original SRM 2686a show that ferrite, periclase, and free lime (when present) may be expected to exhibit the greatest estimate uncertainties.
Ahrens, "Hugoniot equation of state of periclase to 200 GPa," Geophysical Research Letters, vol.
Premier Periclase offers seawater-based large crystal sinter and produces around 70,000 tonnes of sintered magnesia per year.
In these situations, periclase may have formed by dissociation of magnesite according to reaction (1):
* Processing and removing low-magnetic impurities from quartz sand, white synthetic curundum, pegmatite, periclase and other materials with the aim of substantially enhancing the quality of raw materials for glass and abrasives industries.
However, the group said it was writing pounds 10.3 million off the assets of its Ireland-based refractory brick-making business Premier Periclase as it fell into losses and has been temporarily closed.
For years, locals living near the Premier Periclase plant just outside Drogheda have awoken to find a light dusting of a snow-like substance on trees and cars - even in summer.
Beware of this and also of the so-called "periclase" recently offered from China: these gray cauliflowers are sublimates broken from magnesia furnace flues.