CLINTONITE

This article appears in Volume V06, Page 530 of the Encyclopedia Britannica.

Encyclopedia Britannica - Main :: CLI-COM

CLINTONITE , a group of micaceous minerals known as the " brittle micas." Like the micas and chlorites, they are mono-clinic in crystallization and have a perfect cleavage parallel to the flat surface of the plates or scales, but differ markedly from these in the brittleness of the laminae; they are also considerably harder, the hardness of chloritoid being as high as 61 on Mohs' scale. They differ chemically from the micas in containing less silica and no alkalis, and from the chlorites in containing much less water; in many respects they are intermediate between the micas and chlorites.
The following species are distinguished:
Margarite is a basic calcium aluminium silicate, H2CaAl4Si2O12, and is classed by some authors as a lime-mica. It forms white pearly scales, and was at first known as pearl-mica and after-wards as margarite, from apyapirns, a pearl. It is a characteristic associate of

corundum

CORUNDUM

, of which it is frequently an alteration product (facts which suggested the synonymous names corundellite and emerylite), and is found in the emery deposits of Asia

Minor

and the Grecian Archipelago, and with

corundum

CORUNDUM

at several localities in the United States.
Seybertite, Brandisite and Xanthophyllite are closely allied species consisting of basic magnesium, calcium and aluminium silicate, and have been regarded as isomorphous mixtures of a silicate (H2CaM$4Si3O12) and an aluminate (H2CaMgA16O12). Seybertite (the

original

ORIGINAL

clintonite) occurs as reddish-brown to copper-red, brittle, foliated masses in metamorphic limestone at Amity, New

York

YORK
YORK (
HOUSE
- HOUSE
- HOUSE (O. Eng. hiss, a word common to Teutonic languages, cf. Dut. huis, Ger. Haus; in
  Gothic
  - GOTHIC
  it is only found in gudhiss, a temple; it may be ultimately connected with the root of " hide," conceal)
OF)
YORK, EDMUND OF
LANGLEY
- LANGLEY, SAMUEL PIERPONT (1834-1906)
, DUKE OF (1341-1402)
EDWARD
- EDWARD
.html">YORK,
EDWARD
- EDWARD
YORK, FREDERICK
AUGUSTUS
- AUGUSTUS (a name 1 derived from Lat. augeo, increase, i.e. venerable, majestic, Gr. Ee0avr6s)
, DUKE OF (1763-1827)
YORK, RICHARD, DUKE

; brandisite as yellowish-green hexagonal prisms in metamorphic limestone in the Fassathal, Tirol; xanthophyllite as yellow folia and as distinct crystals (waluewite) in chloride schists in the Urals.
Chloritoid has the

formula

H2(Fe,Mg)Al2SiOr. It forms tabular crystals and scales, with indistinct hexagonal outlines, which are often curved or bent and aggregated in rosettes. The colour is dark grey or green; a characteristic feature is the pleochroism, the pleochroic colours varying from yellowish-green to indigo-blue. Hardness, 61; specific gravity, 3.4-3.6. It occurs as isolated scales scattered through schistose rocks and phyllites of dynamo-metamorphic origin. The ottrelites of the phyllites and ottrelite-schists of Ottrez and other localities in the Belgian Ardennes is a manganiferous variety of chloritoid, but owing to enclosed impurities the analyses differ widely from those of typical chloritoid. (L. J. S.)

End of Article: CLINTONITE

If you wish, you can link directly to this article.

<a href="http://jcsm.org/StudyCenter/Encyclopedia/CLI_COM/CLINTONITE.html">
CLINTONITE
</a>

(Previous)
CLINTON, SIR HENRY (c. 1738-1795)

(Next)
CLISSON

JCSM was founded in 1997 and exists to help the community and bring people into a life-changing and productive relationship with Jesus Christ. JCSM offers over 200,000 free web pages, including its weekly inspirational emails that were sent continuously for over a decade.

Jesus Christ Saves Ministries
P.O. Box 9297
San Diego, CA 92169
1-888-887-0417 or Email