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A chain-structure type of clay mineral.
A group of lightweight, tough, fibrous clay minerals showing extensive substitution of aluminum for magnesium.
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 It might be outdated or ideologically biased.



(named after the Palygorskii section of the former Perm’ Mining District), a hydrous magnesium silicate with the approximate chemical formula Mg5[Si4O10]2(OH)2(H2O)4 · 4H2O. Part of the Mg is replaced by Al, and admixtures of Fe3+, Ca, Na, and K oxides are known to occur. According to crystal structure, palygorskite occupies an intermediate position between inosilicates and phyllosilicates. Aggregates exhibit a felted or leather-like structure and occur in the form of crusts. The monoclinic crystals, which resemble thin fibers, are white, light gray, pink, or yellow. Palygorskite has a hardness on Mohs’ scale of 2–2.5 and a density of 2,000–2,300 kg/m3. Its hardness increases substantially after roasting, and the mineral gradually loses water upon heating.

Palygorskite is mainly formed during the weathering of rocks rich in magnesium. It occurs in sedimentary rocks in the form of nests, interstratifications, and, less frequently, large individual aggregates. Palygorskite is used as heat insulation and soundproofing by the construction industry.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Antidiarrheals -- Lomotil, Immodium, Donnagel, Parapectolin
Kaolin pectin mixture (KaoCon/KaoPectate) alone or with paregoric (Parapectolin) and belladonna mixture (Donnagel-PG) are further short-term remedies that should be avoided until after the first 24 hours of diarrhea.
Trans-Scop, Antivert/Bonine, Marezine Antidiarrheals - Lomotil, Immodium, Donnagel, Parapectolin Antisecretory - Robinul, Donnatal, Levsin, Atropine, scopolamine,