PHLOGOPITE  , a See also:

• MINERAL

mineral belonging to the See also:

• GROUP

group of micas (q.v.) . It is a See also:

• MAGNESIUM [symbol Mg, atomic weight 24.32 (0 = 16)]

magnesium See also:

• MICA

mica, differing from See also:

• BIOTITE

biotite in containing only a little See also:

• IRON [symbol Fe, atomic weight 55.85 (0=16)]

iron; the chemical See also:

• FORMULA
• FORMULA (Lat. diminutive of forma, shape, pattern, &c., especially used of rules of judicial procedure)

formula is [H,K,(MgF)]3Mg3Al(SiOi)3 . It crystallizes in the See also:

• MONOCLINIC

monoclinic See also:

• SYSTEM

system, but the crystals are roughly See also:

• DEVELOPED

developed . There is a perfect cleavage parallel to the basal See also:

• PLANE

plane; the cleavage flakes are not quite so elastic as those of See also:

• MUSCOVITE

muscovite . Sometimes it is quite colourless and transparent, but usually of a characteristic yellowish-See also:

• BROWN
• BROWN, CHARLES BROCKDEN (1771-181o)
• BROWN, FORD MADOX (1821-1893)
• BROWN, FRANCIS (1849- )
• BROWN, GEORGE (1818-188o)
• BROWN, HENRY KIRKE (1814-1886)
• BROWN, JACOB (1775–1828)
• BROWN, JOHN (1715–1766)
• BROWN, JOHN (1722-1787)
• BROWN, JOHN (1735–1788)
• BROWN, JOHN (1784–1858)
• BROWN, JOHN (1800-1859)
• BROWN, JOHN (1810—1882)
• BROWN, JOHN GEORGE (1831— )
• BROWN, ROBERT (1773-1858)
• BROWN, SAMUEL MORISON (1817—1856)
• BROWN, SIR GEORGE (1790-1865)
• BROWN, SIR JOHN (1816-1896)
• BROWN, SIR WILLIAM, BART
• BROWN, THOMAS (1663-1704)
• BROWN, THOMAS (1778-1820)
• BROWN, THOMAS EDWARD (1830-1897)
• BROWN, WILLIAM LAURENCE (1755–1830)

brown See also:

• COLOUR (Lat. color, connected with celare, to hide, the root meaning, therefore, being that of a covering)

colour, and often with a silvery lustre on the cleavage surfaces, hence the See also:

• TRADE (O. Eng. trod, footstep, from tredan, to tread; in M. Eng. the forms teed, trod and trade appear, the last in the sense of a beaten track)
• TRADE, BOARD OF

trade name " See also:

• SILVER

silver See also:

• AMBER

amber mica " for some varieties . The name phlogopite is from Gr . 4 Xoynnros (fiery-looking), the mineral being sometimes brownish-red and coppery in See also:

• APPEARANCE (from Lat. apparere, to appear)

appearance . The hardness is 22-3, and the specific gravity 2.78-2.85 . The optic axial plane is parallel to the plane of symmetry and the axial See also:

• 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

angle o°-lo° . Phlogopite occurs chiefly as scales and plates embedded in crystalline limestones of the Archean formation . The mica See also:

• MINED

mined in See also:

• CANADA

Canada and See also:

• CEYLON

Ceylon is mainly phlogopite; and is largely used as an insulator for See also:

• ELECTRICAL
• ELECTRICAL (or ELECTROSTATIC) MACHINE

electrical purposes . In Canada it occurs with See also:

• APATITE

apatite in See also:

• PYROXENE

pyroxene rocks which are intrusive in Laurentian gneisses and crystalline limestones, the See also:

• PRINCIPAL

principal See also:

• MINING

mining See also:

• DISTRICT

district being in See also:

• OTTAWA

Ottawa See also:

• COUNTY (through Norm. Fr. comae, cf. O. Fr. cunte, conk', Mod. Fr. comae, from Lat. comitatus, cf. Ital. comitato, Prov. comtat; see COUNT)

county in See also:

• QUEBEC

Quebec and near See also:

• BURGESS (Med. Lat. burgensis, from burgus, a borough, a town)
• BURGESS, DANIEL (1645-1713)
• BURGESS, THOMAS (1756–1837)

Burgess in See also:

• LANARK

Lanark county, See also:

• ONTARIO
• ONTARIO, LAKE

Ontario .

In Ceylon, the mineral forms irregular See also:

• VEINS

veins, rarely exceeding one or two feet in width, traversing See also:

• GRANULITE (Lat. granulum, a little grain)

granulite, especially near the coptact of this See also:

• ROCK
• ROCK (O.Fr. rake, Sp. rota, Ital. rocca; possibly from a Lat. form rupica, from rupes, rock)
• ROCK, DANIEL (1799–187t)

rock with crystalline See also:

• LIMESTONE

limestone . (L . J .