APLITE  , in See also:

• PETROLOGY

petrology, the name given to intrusive 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 in which See also:

• QUARTZ

quartz and See also:

• FELSPAR, or FELDSPAR

felspar are the dominant minerals . Aplites are usually very See also:

• FINE

fine-grained, 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, 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 or flesh-coloured, and their constituents are visible only with the help of a magnifying See also:

• LENS
• LENS (from Lat. lens, lentil, on account of the similarity of the form of a lens to that of a lentil seed)

lens . Dykes and threads of aplite are very frequently to be observed traversing granitic bosses; they occur also, though in less See also:

• NUMBERS, BOOK OF
• NUMBERS, PARTITION OF

numbers, in syenites, diorites, quartz-diabases and gabbros . Without doubt they have usually a genetic See also:

• AFFINITY (Lat. affinitas, relationship by marriage, from offinis, bordering on, related to; finis, border, boundary)
• AFFINITY, CHEMICAL

affinity to the rocks they intersect . The aplites of See also:

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

granite areas, for example, are the last See also:

• PART

part of the magma to crystallize, and correspond in See also:

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

composition to the quartzo-felspathic aggregates which frll up the interspaces between the See also:

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

early minerals in the See also:

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

main See also:

• BODY

body of the rock . They See also:

• BEAR
• BEAR, BLACK
• BEAR, BROWN
• BEAR, GRIZZLY
• BEAR, ISABELLINE
• BEAR, WHITE

bear a considerable resemblance to the eutectic mixtures which are formed on the cooling of solutions of See also:

• MINERAL

mineral salts, and remain liquid till the excess of either of the components has separated out, finally solidifying en masse when the proper proportions of the constituents and a suitable temperature are reached . The essential components of the aplites are quartz and See also:

• ALKALI

alkali felspar (the latter usually See also:

• ORTHOCLASE

orthoclase or microperthite) . See also:

• CRYSTALLIZATION

Crystallization has been appal., ently rapid (as the rocks are so fine-grained), and the ingredients have solidified almost at the same See also:

• TIME (0. Eng. Lima, cf. Icel. timi, Swed. timme, hour, Dan. time; from the root also seen in " tide," properly the time of between the flow and ebb of the sea, cf. O. Eng. getidan, to happen, " even-tide," &c.; it is not directly related to Lat. tempus)
• TIME, MEASUREMENT OF
• TIME, STANDARD

time . Hence their crystals are rather imperfect and See also:

• FIT

fit closely to one another in a sort of fine See also:

• MOSAIC (corresponding to Lat. opus musivum, from Gr. µovoeiov, an artificial grotto often decorated with mosaics; the word is only found in the sense of mosaic in late Greek, which generally uses k oXI yrlµa)

mosaic of nearly equi-dimensional grains . Porphyritic felspars occur occasionally and quartz more seldom; but the relation of the aplites to quartz-porphyries, granophyres and felsites is very See also:

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

close, as all these rocks have nearly the same chemical composition . Yet the aplites associated with diorites and quartz-diabases differ in See also:

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

minor respects from the See also:

• COMMON

common aplites, which accompany granites . The See also:

• ACCESSORY

accessory minerals of these rocks are principally See also:

• OLIGOCLASE

oligoclase, See also:

• MUSCOVITE

muscovite, See also:

• APATITE

apatite and See also:

• ZIRCON

zircon .

See also:

• BIOTITE

Biotite and all ferromagnesian minerals rarely appear in them, and never are in considerable amount . Riebeckitegranites (paisanites) have close See also:

• AFFINITIES

affinities to aplites, shown especially in the prevalence of alkali felspars . See also:

• TOURMALINE

Tourmaline also occurs in some aplites . The rocks of this See also:

• GROUP

group are very frequent in all areas where masses of granite are known . They See also:

• FORM (Lat. forma)

form dykes and irregular See also:

• VEINS

veins which may be only a few inches or many feet in See also:

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

diameter . Less frequently aplite forms See also:

• STOCKS

stocks or bosses, or occupies the edges or ,irregular portions of the interior of outcrops of granite . The See also:

• SYENITE

syenite-aplites consist mainly of alkali felspar; the See also:

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

diorite-aplites of See also:

• PLAGIOCLASE

plagioclase; there are See also:

• NEPHELINE

nepheline-bearing aplites which intersect some elaeolite-syenites . In all cases they bear the same relation to the See also:

• PARENT, SIMON NAPOLEON (1855– )

parent masses . By increase of quartz aplites pass gradually, in a few localities, through highly quartzose modifications (beresite, &c.) into quartz veins . (J . S .