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C. An uniform rock, more or less laminar, with a fracture between granular and splintery.

D. The quartz and felspar both in distinct grains and in various proportions.

a. Highly compacted, and cemented by silex,

or quartz.

b. Gravelly, or sandy, sometimes loose. of quartz and mica.

A. Compact quartz, with scales of mica interspersed.

a. The quartz opaque.

b.

▬▬hyaline. (aventurine)

B. Laminar: occasioned by the position of the mica.

a. The mica in distinct scales, dispersed, but parallel.

b.. The mica forming distinct laminæ.

This latter passes into mica slate.

Of quartz and blue schistose clay.

A. The two substances in alternate laminæ.

B. Quartz, arenaceous, and minutely interlaminated with clay, similar to the sandstone accompanying coal.

C. Quartz sand and blue clay intimately mixed. This last passes into fine grey wacke schist.

Third Division.

Conglomerate: with more than two ingredients.

A. Quartz sand alone, or sand and gravel of quartz and felspar, with imbedded pebbles or fragments of quartz.

B. The same, with fragments of argillite.

C. The same, with fragments of mica slate, or with both.

These pass into coarse grey wacke.

SYNOPSIS OF CHLORITE SCHIST.
First Division.

Simple: of Chlorite only.

A. Foliated Chlorite; plain or undulated; with minute, or with large undulations.

Second Division.

Compound: of two ingredients.

Foliated or simple laminar and alternating.
A. Foliated chlorite with laminar quartz.

B.

C.

D.

-granular quartz.

-laminar felspar,

grains or imperfect

crystals of felspar disposed in a laminar manner. Granularly laminar: mixed.

A. Scaly or imperfectly foliated chlorite with quartz sand.

ture.

d. Large grained, with a rough granular frac

b. Small grained, with a homogeneous aspect, and often scarcely fissile.

c. The preceding varieties, passing into grey wacke schist, and into argillite.

B. Scaly chlorite with large grains of quartz. Similar in structure and appearance to mica slate E. 1st div: 2d subdiv.

C. Scaly chlorite, with large imperfect crystals of felspar: similar in structure to the preceding, and resembling granitic-gneiss.

D. Scaly chlorite, highly compacted, with minute grains of felspar interspersed : difficulty fissile: occasionally granular, and fibrous.

E. Scaly chlorite with hornblende, intermixed or imbedded, and passing into hornblende schist.

F. Scaly chlorite intermixed with actynolite: very compact, sometimes fibrous, difficulty fissile. G Scaly chlorite with mica: passing into mica slate.

Third Division.

Compound: with more than two ingredients. Laminar, alternating.

A. Foliated chlorite, felspar and quartz.

This occurs in the series of gneiss, and is there

introduced.

Granularly laminar; mixed.

A. Scaly chlorite, quartz, and felspar.

B.

C.

felspar and mica.

hornblende and mica.

D.

hornblende, quartz, and

green compact felspar.

SYNOPSIS OF TALCOSE SCHIST.

First Division.

Simple of one ingredient.

A. Schistose talc.

a. Scaly and foliated.

b. Scaly and semigranular.

Minutely scaly-granular and indurated:

potstone of some mineralogists.

This variety passes into serpentine, and has there been mentioned.

Second Division.

Compound: of two ingredients.

A. Talc, and quartz: foliated; the quartz variously disposed, and the rock resembling mica schist, into which it passes.

B. Talc, and foliated or scaly chlorite; passing into chlorite schist.

C. Talc and felspar.

D. Talc and argillite: passing into argillite, under which head it has been mentioned.

E. Talc and serpentine: passing into serpentine.
Third Division.

Compound of three ingredients.

:

A. Talc, quartz, and felspar.

B. Talc, quartz, and mica.

SYNOPSIS OF HORNBLENDE ROCKS.
First Division.

Simple of hornblende alone.

A. Very compact, with a smooth and dull fracture the particles being scarcely discernable.

:

B. Granular, from small irregular aggregated crystals of different degrees of fineness.

C. Scaly, from an aggregation of flat crystals. D. Flat, continuously laminar.

E. Fibrous.

a Simply fibrous, and with snort fibres.

b. Fibrous radiated.

c. Very fine fibrous and silky.

F. The texture so fine that it loses its character, and passes into argillite.

The above are sometimes imperfectly, or not at all fissile, and then form what is usually named hornblende rock.

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