UNIVERSITY OF CALIFORNIA PUBLICATIONS

BULLETIN OF THE DEPARTMENT OF

GEOLOGY

Vol. 5, No. 23, pp. 331-380, Pls. 27-39 ANDREW C. LAWSON, Editor





BENITOITE, ITS PARAGENESIS AND

MODE OF OCCURRENCE.

BY
GEORGE DAVIS LOUDERBACK.

WITH CHEMICAL ANALYSES BY
WALTER C. BLASDALE


CONTENTS
PAGE
Introduction332
The Locality333
General Geological Surroundings334
Occurrence336
Effects of Earth movement and Pressure337
Size and Attitude of Outcrop339
General Relations of Minerals in Veins340
The Minerals of the Deposit341
Benitoite341
Crytsallography341
Habits344
Symmetry345
Etch Figures345
Natural Etching347
Physical Properties347
Chemical Characters349
Benitoite as a Gem353
Neptunite354
Crytsallography354
Physical Characters356
Chemical Characters357
Natrolite357
Copper Minerals359
Other Minerals360
Amphiboles360
Albite361
Aegyrine363
Calcite and Aragonite363
Manganese Dioxide363
Country in which the Veins Formed364
Sequence of Events366
Distribution of Minerals in Veins368
Relation to Serpentine369
General Discussion370

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