See also:

• GRANITE (adapted from the Ital. granite, grained; Lat. granum, grain)

GRANITE (adapted from the Ital. granite, grained; See also:

• LAT

Lat. granum, See also:

• GRAIN (derived through the French from Lat. granum, seed, from an Aryan root meaning " to wear down," which also appears in the common Teutonic word " corn ")

grain)  , the See also:

• GROUP

group designation for a See also:

• FAMILY

family of igneous rocks whose essential characteristics are that they are of See also:

• ACID (from the Lat. root ac-, sharp; acere, to be sour)

acid See also:

• COMPOSITION
• COMPOSITION (Lat. compositio, from componere, to put together)

composition (containing high percentages of See also:

• SILICA

silica), consist principally of See also:

• QUARTZ

quartz and See also:

• FELSPAR, or FELDSPAR

felspar, with some See also:

• MICA

mica, See also:

• HORNBLENDE

hornblende or See also:

• AUGITE

augite, and are of holocrystalline or " granitoid " structure . In popular usage the See also:

• TERM

term is given to almost any crystalline 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 which resembles See also:

• GRANITE (adapted from the Ital. granite, grained; Lat. granum, grain)

granite in See also:

• APPEARANCE (from Lat. apparere, to appear)

appearance or properties . Thus syenites, diorites, gabbros, diabases, porphyries, See also:

• GNEISS

gneiss, and even limestones and See also:

• DOLOMITES, THE

dolomites, are bought and sold daily as "granites." True granites are See also:

• COMMON

common rocks, especially among the older strata of the See also:

• EARTH
• EARTH (a word common to Teutonic languages, cf. Ger. Erde, Dutch aarde, Swed. and Dan. jord; outside Teutonic it appears only in the Gr. 'pq'e, on the ground; it has been connected by some etymologists with the Aryan root ar-, to plough, which is seen in
• EARTH, FIGURE OF
• EARTH, FIGURE OF THE

earth's crust . They have See also:

• GREAT

great variety in See also:

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

colour and See also:

• GENERAL
• GENERAL (Lat. generalis, of or relating to a genus, kind or class)

general appearance, some being See also:

• WHITE
• WHITE, ANDREW DICKSON (1832– )
• WHITE, GILBERT (1720–1793)
• WHITE, HENRY KIRKE (1785-1806)
• WHITE, HUGH LAWSON (1773-1840)
• WHITE, JOSEPH BLANCO (1775-1841)
• WHITE, RICHARD GRANT (1822-1885)
• WHITE, ROBERT (1645-1704)
• WHITE, SIR GEORGE STUART (1835– )
• WHITE, SIR THOMAS (1492-1567)
• WHITE, SIR WILLIAM ARTHUR (1824--1891)
• WHITE, SIR WILLIAM HENRY (1845– )
• WHITE, THOMAS (1628-1698)
• WHITE, THOMAS (c. 1550-1624)

white or See also:

• GREY, CHARLES GREY, 2ND EARL (1764-1845)
• GREY, HENRY GREY, 3RD EARL (1802-1894)
• GREY, LADY JANE (1537-1554)
• GREY, SIR EDWARD
• GREY, SIR GEORGE (1812–1898)

grey, while others are See also:

• PINK

pink, greenish or yellow: this depends mainly on the See also:

• STATE
• STATE, GREAT OFFICERS OF

state of preservation of their felspars, which are their most abundant minerals, and partly also on the relative proportion in which they contain See also:

• BIOTITE

biotite and other dark coloured silicates . Many granites have large rounded or angular crystals of felspar (Shap granite, many Cornish granites), well seen on polished faces . Others show an elementary foliation or banding (e.g . See also:

• ABERDEEN
• ABERDEEN, GEORGE GORDON, 1ST EARL O (1637-1720)
• ABERDEEN, GEORGE HAMILTON GORDON, 4TH EARL

Aberdeen granite) . Rounded or See also:

• OVAL (Lat. ovum, egg)

oval dark patches frequently appear in the granitic See also:

• MATRIX

matrix of many Cornish rocks of this group . In the See also:

• FIELD (a word common to many West German languages, cf. Ger. Feld, Dutch veld, possibly cognate with O.E. f olde, the earth, and ultimately with root of the Gr. irAaror, broad)
• FIELD, CYRUS WEST (1819-1892)
• FIELD, DAVID DUDLEY (18o5-1894)
• FIELD, EUGENE (1850-1895)
• FIELD, FREDERICK (18o1—1885)
• FIELD, HENRY MARTYN (1822-1907)
• FIELD, JOHN (1782—1837)
• FIELD, MARSHALL (183 1906)
• FIELD, NATHAN (1587—1633)
• FIELD, STEPHEN JOHNSON (1816-1899)
• FIELD, WILLIAM VENTRIS FIELD, BARON (1813-1907)

field granite usually occurs in great masses, covering wide areas . These are generally elliptical or nearly circular and may be 20 M. in See also:

• DIAMETER (from the Cr. &a, through, µErpov, measure)

diameter or more . In the same See also:

• DISTRICT

district See also:

• SEPARATE

separate areas or " bosses " of granite may he found, all having much in common in their mineralogical and structural features, and such See also:

• GROUPS
• GROUPS, THEORY

groups have probably all proceeded from the same See also:

• FOCUS (Latin for " hearth " or " fireplace ")

focus or deep-seated source . Towards their margins these granite outcrops often show modifications by which they pass into See also:

• DIORITE (from the Gr. S&oi4eiv to distinguish, from hA through, Epos, a boundary)

diorite or See also:

• SYENITE

syenite, &c.; they may also be finer grained (like porphyries) or See also:

• RICH, BARNABE (c. 1540-1617)
• RICH, CLAUDIUS JAMES (1787-1821)
• RICH, JOHN (1692-1761)
• RICH, PENELOPE, LADY (c. 1562–1607)
• RICH, RICHARD, 1ST BARON RICH (1490?-1567)

rich in See also:

• TOURMALINE

tourmaline, or intersected by many See also:

• VEINS

veins of See also:

• PEGMATITE (from Gr. 1r3 y ea, a bond)

pegmatite .

From the See also:

• MAIN (from the Aryan root which appears in " may " and " might," and Lat. magnus, great)
• MAIN (Lat. Moenus)

main granite dikes or veins often run out into the surrounding rocks, thus proving that the granite is intrusive and has forced its way upwards by splitting apart the strata among which it lies . Further See also:

• EVIDENCE (Lat. evidentia, evideri, to appear clearly)

evidence of this is afforded by the alteration which the granite has produced through a See also:

• ZONE (Gr. 'WV77, a girdle, from 'wvvLvay to gird)

zone which varies from a few yards to a mile or more in breadth around it . In the vicinity of intrusive granites slates become converted into hornfelses containing biotite, chiastolite or See also:

• ANDALUSITE

andalusite, See also:

• SILLIMANITE

sillimanite and a variety of other minerals; See also:

• LIME
• LIME (O. Eng. lim, Lat. limes, mud, from linere, to smear)

lime-stones recrystallize as See also:

• MARBLES

marbles, and all rocks, according to their composition, are more or less profoundly modified in such a way as to prove that they have been raised to a high temperature by proximity to the molten intrusive See also:

• MASS (O.E. maesse; Fr. messe; Ger. Messe; Ital. messa; from eccl. Lat. missa)
• MASS, IN

mass . Where exposed in cliffs and other natural sections many granites have a rudely columnar appearance . Others See also:

• WEATHER (O. Eng. weder; the word is common to Teutonic languages; cf. Du. weder, Dan. veir, Icel. ve8r, and Ger. Wetter and Gewitter, storm; the root is wa- to blow, from which is derived " wind ")

weather into large cuboidal blocks which may produce structures resembling cyclopean See also:

• MASONRY

masonry . The tors of the See also:

• WEST
• WEST, BENJAMIN (1738-1820)
• WEST, NICHOLAS (1461-1533)

west of See also:

• ENGLAND
• ENGLAND, THE CHURCH OF

England are of this nature . These See also:

• DIFFERENCES, CALCULUS OF (Theory of Finite Differences)

differences depend on the disposition of the See also:

• JOINT (through Fr. from Lat. junctum, jungere, to join)

joint cracks which See also:

• TRAVERSE

traverse the rock and are opened up by the See also:

• ACTION

action of See also:

• FROST (a common Teutonic word, cf. Dutch, vorst, Ger. Frost, from the common Teutonic verb meaning " to freeze," Dutch, vriezcn, Ger. frieren; the Indo-European root is seen in Lat. pruina, hoar-frost, cf. prurire, to itch, burn, pruna, burning coal, Sans
• FROST, WILLIAM EDWARD (1810–1877)

frost and weathering . The See also:

• MAJORITY (Fr. majorite; Med. Lat. majoritas; Lat. major, greater)

majority of granites are so coarse in See also:

• GRAIN (derived through the French from Lat. granum, seed, from an Aryan root meaning " to wear down," which also appears in the common Teutonic word " corn ")

grain that their See also:

• PRINCIPAL

principal component minerals may be identified in the See also:

• HAND
• HAND (a word common to Teutonic languages; cf. Ger. Hand, Goth. handus)
• HAND, FERDINAND GOTTHELF (1786-185r)

hand specimens by the unaided See also:

• EYE
• EYE (O. Eng. edge, Ger. Auge; derived from an Indo-European root also seen in Lat. oc-ulus, the organ of vision (q.v.)

eye . The felspar is pearly, white or pink, with smooth cleaved surfaces; the quartz is usually transparent, glassy with rough irregular fractures; the micas appear as shining See also:

• BLACK
• BLACK, ADAM (1784-1874)
• BLACK, JEREMIAH SULLIVAN (1810–1883)
• BLACK, WILLIAM (1841-1898)

black or white flakes . Very coarse granites are called pegmatite or See also:

• GIANT (O.E. geant, through Fr. giant, O.Fr. gaiant, jaiant, jeant, med. pop. Lat. gagante—cf. Ital. gigante—by assimilation from gigantem, ace. of Lat. gigas, Gr. yiyas)

giant granite, while very See also:

• FINE

fine granites are known as microgranites (though the latter term has also been applied to certain porphyries) . Many granites show pearly scales of white mica; others contain dark See also:

• GREEN, A
• GREEN, ALEXANDER HENRY (1832—1896)
• GREEN, DUFF (1791—1875)
• GREEN, JOHN RICHARD (1837—1883)
• GREEN, MATTHEW (1696-1737)
• GREEN, THOMAS HILL (1836-1882)
• GREEN, VALENTINE (1739–1813)
• GREEN, WILLIAM HENRY (.1825–1900)

green or black hornblende in small prisms . Reddish grains of See also:

• SPHENE

sphene or of See also:

• GARNET
• GARNET, or GARNETT, HENRY (1555—1606)

garnet are occasionally visible .

In the tourmaline granites prisms of black See also:

• SCHORL

schorl occur either singly or in stellate groups . The parallel banded structures of many granites, which may be See also:

• ORIGINAL

original or due to crushing, connect these rocks with the granite gneisses or orthogneisses . Under the See also:

• MICROSCOPE (Gr. µucp6s, small, asenreiv, to %view)

microscope the felspar is mainly See also:

• ORTHOCLASE

orthoclase with perthite or See also:

• MICROCLINE

microcline, while a small amount of See also:

• PLAGIOCLASE

plagioclase (ranging from See also:

• OLIGOCLASE

oligoclase to See also:

• ALBITE

albite) is practically never absent . 'These minerals are often clouded by a See also:

• DEPOSIT (Lat. depositurn, from deponere, to lay down, to put in the care of)

deposit of fine mica and See also:

• KAOLIN

kaolin, due to weathering . The quartz is transparent, irregular in See also:

• FORM (Lat. forma)

form, destitute of cleavage, and is filled with very small cavities which contain a fluid, a See also:

• MOBILE

mobile bubble and sometimes a See also:

• MINUTE
• MINUTE (Lat. minutes, small; minuere, to make less)

minute crystal . The micas, 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 and white, are often in parallel growth . The hornblende of granites is usually See also:

• PALE (through Fr. pal, from Lat. palms, a stake, for paglus, from the stem pag- of pangere, to fix; " pole " is from the same original source)

pale green in See also:

• SECTION
• SECTION (Lat. sectio, cutting, secare, to cut)

section, the augite and See also:

• ENSTATITE

enstatite nearly colourless . 'Tourmaline may be brown, yellow or See also:

• BLUE (common in different forms to most European languages)

blue, and often the same crystal shows zones of different See also:

• COLOURS, MILITARY

colours . See also:

• APATITE

Apatite, See also:

• ZIRCON

zircon and See also:

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

iron oxides, in small crystals, are always See also:

• PRESENT

present . Among the less common accessories may be mentioned pinkish garnets; andalusite in small pleochroic crystals; colourless grains of See also:

• TOPAZ

topaz; six-sided See also:

• COMPOUND
• COMPOUND (from Lat. componere, to combine or put together)

compound crystals of cordierite, which weather to dark green pinite; blue-black hornblende (riebeckite), See also:

• BERYL

beryl, tinstone, orthite and See also:

• PYRITES

pyrites . The sequence of See also:

• CRYSTALLIZATION

crystallization in the granites is of a normal type, and may be ascertained by observing the perfection with which the different minerals have crystallized and the See also:

• ORDER
• ORDER (through Fr. ordre, for earlier ordene, from Lat. ordo, ordinis, rank, service, arrangement; the ultimate source is generally taken to be the root seen in Lat. oriri, rise, arise, begin; cf. " origin ")
• ORDER, HOLY

order in which they enclose one another . Zircon, apatite and iron oxides are the first; their crystals are small, very perfect and nearly See also:

• FREE

free from enclosures; they are followed by hornblende and biotite; if See also:

• MUSCOVITE

muscovite is present it succeeds the brown mica .

Of the felspars the plagioclase separates first and forms well- ' shaped crystals of which the central parts may be more basic than the See also:

• OUTER

outer zones . Last come orthoclase, quartz, microcline and micropegmatite, which fill up the irregular spaces See also:

• LEFT

left between the earlier minerals . Exceptions to this sequence are unusual; sometimes the first of the felspars have preceded the hornblende or biotite which may envelop them in ophitic manner . below:- An earlier See also:

• GENERATION (from Lat. generare, to beget, procreate; genus, stock, race)

generation of felspar, and occasionally also of quartz, maybe represented by large and perfect crystals of these minerals giving the rock a porphyritic See also:

• CHARACTER (Gr. xapareri7p, from xap&crew, to scratch)

character . Many granites have suffered modification by the action of vapours emitted during cooling . Hydrofluoric and boric emanations exert a profound See also:

• INFLUENCE (Late Lat. influentia, from influere, to flow in)

influence on granitic rocks; their felspar is resolved into aggregates of kaolin, muscovite and quartz; tourmaline appears, largely replacing the brown mica; topaz also is not uncommon . In this way the rotten granite or See also:

• CHINA

china See also:

• STONE
• STONE (0. Eng. shin; the word is common to Teutonic languages, cf. Ger. Stein, Du. steen, Dan. and Swed. sten; the root is also seen in Gr. aria, pebble)
• STONE, CHARLES POMEROY (1824-1887)
• STONE, EDWARD JAMES (1831-1897)
• STONE, FRANK (1800-1859)
• STONE, GEORGE (1708—1764)
• STONE, LUCY [BLACKWELL] (1818-1893)
• STONE, MARCUS (184o— )
• STONE, NICHOLAS (1586-1647)

stone, used in pottery, originates; and over considerable areas kaolin replaces the felspar and forms valuable See also:

• SOURCES

sources of china See also:

• CLAY (from O. Eng. claeg, a word common in various forms to Teutonic languages, cf. Ger. Klei)
• CLAY, CASSIUS MARCELLUS (1810-1903)
• CLAY, CHARLES (1801–1893)
• CLAY, FREDERIC (1838–1889)
• CLAY, HENRY (1777–1852)

clay . Veins of quartz, tourmaline and See also:

• CHLORITE

chlorite may traverse the granite, containing tinstone often in workable quantities . These veins are the principal sources of See also:

• TIN (Lat.- stannum, whence the chemical symbol " Sn "; atomic weight =117.6, 0=16)

tin in See also:

• CORN (a common Teutonic word; cf. Lat. granum, seed, grain)
• CORN (fromm Lat. corms, horn)

Corn-See also:

• WALL (O. Eng. weal, weall, Mid. Eng. wal, wane, adapted from Lat. vallum, rampart; the original O. Eng. word for a wall was wag or tenth)
• WALL, RICHARD (1694-1778)

wall, but the same changes may appear in the See also:

• BODY

body of the granite without being restricted to veins, and tinstone occurs also as an original constituent of some granite pegmatites . Granites may also be modified by crushing . Their crystals tend to lose their original forms and to break into mosaics of interlocking grains . The latter structure is very well seen in the quartz, which is a brittle See also:

• MINERAL

mineral under stress .

White mica develops in the felspars . The larger crystals are converted into lenticular or elliptical " augen," which may be shattered through-out or may have a peripheral seam of small detached granules surrounding a still undisintegrated core . Streaks of "granulitic " or pulverized material See also:

• WIND
• WIND (a common Teut. word, cognate with Skt. vats, Lat. ventus, cf. " weather," to be of course distinguished from to " wind," to coil or twist, O.Eng. windan, cf. "wander," "wend," &c.)

wind irregularly through the rock, giving it a roughly foliated character . The interesting structural variation of granite in which there are spheroidal masses surrounded by a granitic matrix is known as " orbicular granite." The spheroids range from a fraction of an See also:

• INCH (O. Eng. ynce from Lat. uncia, a twelfthpart; cf. " ounce," and see As)

inch to a See also:

• FOOT

foot in diameter, and may have a felspar crystal at the centre . Around this there maybe several zones, alternately lighter and darker in colour, consisting of the essential minerals of the rock in different proportions . Radiate arrangement is sometimes visible in the crystals of the whole or See also:

• PART

part of the See also:

• SPHEROID (Gr. c4aipa-etbis, like a sphere)

spheroid . Spheroidal granites of this sort are found in See also:

• SWEDEN
• SWEDEN [Sverige]
• SWEDEN, NORWAY AND

Sweden, See also:

• FINLAND (Finnish, Suomi or Suomenmaa)

Finland, See also:

• IRELAND
• IRELAND, CHURCH
• IRELAND, CHURCH OF
• IRELAND, JOHN (1761-1842)
• IRELAND, JOHN (1838- )
• IRELAND, WILLIAM HENRY (1777-1835)

Ireland, &c . In other cases the spheroids are simply dark rounded lumps of biotite, in fine scales . These are probably due to the See also:

• ADHESION (from Lat. adhaerere, to adhere)

adhesion of the biotite crystals to one another as they separated from the rock magma at an See also:

• EARLY
• EARLY, JUBAL ANDERSON (1816-1894)

early See also:

• STAGE (Fr. 6/age; from Lat. stare, to stand)

stage in its crystallization . The Rapakiwi granites of Finland have many See also:

• ROUND (O. Fr. rond, Lat. rotundus, the Fr. is the source also of Du. rond; Ger., Swed., Dan. and Nor. rond)

round or ovoidal felspar crystals scattered through a granitic matrix . These larger felspars have no crystalline outlines and consist of orthoclase or microcline surrounded by See also:

• BORDERS, THE

borders of white oligoclase . Often they enclose dark crystals of biotite and hornblende, arranged zonally .

Many of these granites contain tourmaline, fluorite and See also:

• MONAZITE

monazite . In most granite masses, especially near their contacts with the surrounding rocks, it is common to find enclosures of altered sedimentary or igneous materials which are more or less dissolved and permeated by the granitic magma . The chemical composition oY a See also:

• YEW (Taxus baccata)

Yew granites from different parts of the See also:

• WORLD

world is given below:- SiO2 . Al2O, . FezO3 . FeO . MgO . CaO . Na,O . K2O . I . 74.69 16.21 1.16 0.48 o•28 1.18 3'64 II .

71.33 II .18 3.96 1.45 o•88 2.10 3'51 3'49 IV . 76.12 12.18 1.21 0.72 1.12 1.54 2'55 3.21 V . 73.90 13'65 0.28 0.42 0.14 0.23 2'53 7'99 VI . 68.87 16.62 0.43 2-72 I.6o 0.71 1.80 6.48 I . Carn Brea, See also:

• CORNWALL

Cornwall (See also:

• PHILLIPS
• PHILLIPS, ADELAIDE (1833-1882)
• PHILLIPS, EDWARD (163o-1696)
• PHILLIPS, JOHN (1800—1874)
• PHILLIPS, SAMUEL (1814—1854)
• PHILLIPS, STEPHEN (1868– )
• PHILLIPS, THOMAS (1770-1845)
• PHILLIPS, WENDELL (1811-1884)

Phillips) ; II . Mazaruni, Brit . See also:

• GUIANA (Guyana, Guayana')

Guiana (See also:

• HARRISON
• HARRISON, BENJAMIN
• HARRISON, FREDERIC (1831— )
• HARRISON, JOHN (1693—1776)
• HARRISON, THOMAS (16o6-166o)
• HARRISON, THOMAS ALEXANDER (1853– )
• HARRISON, WILLIAM (1534–1593)
• HARRISON, WILLIAM HENRY (1773–1841)

Harrison); III . Redo, near Alne, Vesternorrland, Sweden (Holmquist) ; IV . Abruzzen, a group of hills in the See also:

• RIESENGEBIRGE (Bohemian Krkonose)

Riesengebirge (Milch) ; V . Pikes See also:

• PEAK, THE

Peak, See also:

• COLORADO

Colorado (See also:

• MATTHEWS, STANLEY (1824-1889)

Matthews); VI . See also:

• WILSON, ALEXANDER (1766-1813)
• WILSON, HENRY (1812–1875)
• WILSON, HORACE HAYMAN (1786–1860)
• WILSON, JAMES (1742—1798)
• WILSON, JAMES (1835— )
• WILSON, JAMES HARRISON (1837– )
• WILSON, JOHN (1627-1696)
• WILSON, JOHN (178 1854)
• WILSON, ROBERT (d. 1600)
• WILSON, SIR DANIEL (1816–1892)
• WILSON, SIR ROBERT THOMAS (1777—1849)
• WILSON, SIR WILLIAM JAMES ERASMUS
• WILSON, THOMAS (1663-1755)
• WILSON, THOMAS (c. 1525-1581)
• WILSON, WOODROW (1856— )

Wilson's See also:

• CREEK
• CREEK (Mid. Eng. crike or creke, common to many N. European languages)

Creek, near Omeo, See also:

• VICTORIA
• VICTORIA (or VITTORIA), TOMMASSO LUDOVICO DA (C. I540-C. 1613)
• VICTORIA [ALEXANDRINA VICTORIA]

Victoria (Howitt) . Only the most important components are shown in the table, but all granites contain also small amounts of zirconia, See also:

• TITANIUM [symbol Ti, atomic weight 48.1 (0 = 16)]

titanium See also:

• OXIDE

oxide, phosphoric acid, See also:

• SULPHUR

sulphur, oxides of See also:

• BARIUM (symbol Ba, atomic weight 137'37 [0=16])

barium, See also:

• STRONTIUM [Symbol Sr, atomic weight 87.62 (0=16)]

strontium, See also:

• MANGANESE (symbol Mn; atomic weight, 54.93 (0=16)], a metallic chemical element. Its dioxide (pyrolusite)

manganese and See also:

• WATER

water .

These are in all cases less than 1%, and usually much less than this, except the water, which may be 2 or 3 % in weathered rocks . From the chemical composition it may be computed that granites contain, on an See also:

• AVERAGE

average, 35 to 55 % of quartz, 20 to 30 % of orthoclase, 20 to 30 % of plagioclase felspar (including the albite of microperthite) and 5 to 10 % of ferromagnesian silicates and See also:

• MINOR
• MINOR (Lat. for smaller, lesser)
• MINOR, ROBERT CRANNELL (1839-1904)

minor accessories such as apatite, zircon, sphene and iron oxides . The aplites, pegmatites, graphic granites and muscovite granites are usually richest in silica, while with increase of biotite and hornblende, augite and enstatite the analyses show the presence of more See also:

• MAGNESIA

magnesia, iron and lime . In the weathering of granite the quartz suffers little See also:

• CHANGE (derived through the Fr. from the Late Lat. cambium, cambiare, to barter; the ultimate derivation is probably from the root which appears in the Gr. «a urmu', to bend)

change; the felspar passes into dull cloudy, soft aggregates of kaolin, muscovite and secondary quartz, while chlorite, quartz and See also:

• CALCITE

calcite replace the biotite, hornblende and augite . The rock often assumes a rusty brown colour from the liberation of the oxides of iron, and the decomposed mass is friable and can easily be dug with a See also:

• SPADE

spade; where the granite has been cut by joint planes not too See also:

• CLOSE
• CLOSE (from Lat. clausum, shut)
• CLOSE, MAXWELL HENRY (1822-1903)

close together weathering proceeds from their surfaces and large rounded blocks may be left embedded in rotted materials . The amount of water in the rock increases and part of the alkalis is carried away in See also:

• SOLUTION (from Lat. solvere, to loosen, dissolve)

solution; they form valuable sources of mineral See also:

• FOOD
• FOOD (like the verb " to feed," from a Teutonic root, whence O. Eng. foda; cf. " fodder "; connected with Gr. lrareicOae, to feed)

food to See also:

• PLANTS

plants . The chemical changes are shown by the following analyses: Analyses of I., fresh grey granite; II. brown moderately See also:

• FIRM

firm granite; III. residual See also:

• SAND
• SAND, GEORGE (1804-1876)

sand, produced by the weathering of the same mass (anal . G . P . See also:

• MERRILL

Merrill) . The differences are surprisingly small and are principally an increase in the water and a diminution in the amount of alkalis and lime together with the oxidation of the ferrous oxide . (J .

S .