ALBITE

This article appears in Volume V01, Page 512 of the Encyclopedia Britannica.

Encyclopedia Britannica - Main :: AJA-ALL

ALBITE , a

mineral

MINERAL

of the felspar group, belonging to the division of the plagioclases (q.v.). It is a sodium and aluminium silicate, NaAlSi3Os, and crystallizes in the anorthic system. Like all the felspars it possesses two cleavages, one perfect and the other less so, which are here inclined at an

angle

ANGLE (from the Lat. angulus, a corner, a diminutive, of which the primitive form, angus, does not occur in Latin; cognate are the Lat. angere, to compress into a bend or to strangle, and the Gr. ayKOS, a bend; both connected with the Aryan root ank-, to

of 86 24'. On the more perfect cleavage, which is parallel to the basal plane (P), is a system of fine striations, parallel to the second cleavage (M), due to twinning according to the albite law " (

figs

FIGS

. r and 2). The hard-
ness is 6, and the specific gravity 2.63. The colour is usually pure white, hence the name (from the Lat. albus) for the species.
Albite forms an essential constituent of many acidic igneous and crystalline rocks;
in granites, diorites, andesites, &c., it occurs as a primary

mineral

MINERAL

, whilst in crystalline schists, phyllites and crystalline limestones it is of secondary (metamorphic) origin. The beautifully developed crystals so abundant in crystal-lined crevices of Alpine granites and gneisses have been deposited, with other minerals, from solution; the crystals lining veins in the slates of

Tintagel

TINTAGEL, or TREVENA

Cornwall

CORNWALL

have the same origin.
Several varieties of albite are distinguished, of which the following may be here specially mentioned. Pericline (from the Gr. trepu(from the Gr. 7repurTEpa, a dove) is characterized by a beautiful bluish sheen, somewhat resembling that seen on the neck of a pigeon; it is found mainly in Ontario. Aventurine and moonstone varieties occur, though these special appearances are more usually displayed by the oligoclase and orthoclase felspars respectively. (L. J. S.)
'ALSO, JOSEPH, a Spanish Jewish theologian of the ,5th century. He was author of a very popular book on the philosophy of Judaism, entitled 'Iqqarim or Fundamentals. Maimonides in the 12th century had formulated the principles of Judaism in thirteen articles; Albo reduced them to three: (i) The Existence of God, (ii) Revelation and (iii) Divine Retribution. Albo set the example of minimizing Messianism in the formulation of Jewish beliefs. Though he fully maintained the Mosaic author-ship of the Law and the binding force of tradition, he discriminated between the essential and the non-essential in the practices and beliefs of Judaism. An English translation of the 'Iqqarim appeared in the Hebrew Review, vols. i.-iii.

End of Article: ALBITE

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

<a href="http://jcsm.org/StudyCenter/Encyclopedia/AJA_ALL/ALBITE.html">
ALBITE
</a>

(Previous)
ALBION (in Ptolemy 'A)wviw; Lat. Albion, Pliny ...

(Next)
ALBOIN (d. 572 or 573)

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