SPHENE  , a See also:

• MINERAL

mineral consisting of See also:

• CALCIUM [symbol Ca, atomic weight 40.0 (o= x6)]

calcium titan-silicate, CaTiSiO5, crystallizing in the See also:

• MONOCLINIC

monoclinic See also:

• SYSTEM

system . The crystals vary considerably in See also:

• HABIT (through the French from Lat. habitus, from habere, to have, hold, or, in a reflective sense, to be in a certain condition; in many of the English senses the French use habitude, not habit)

habit, but are generally thin and See also:

• WEDGE (O. Eng. wecg, a mass of metal, cognate with Dutch wig, wigge, Dan. vaegge, &c.; in Lith. the cognate form outside Teut. is found in wagis, a peg, spigot; there is no connexion with " weigh," " weight," which must be referred to the root wegh, to li

wedge-shaped; hence the name sphene, from the See also:

• GREEK
• GREEK, ETRUSCAN AND

Greek a¢ v (a wedge), given by R . J . See also:

• HAUY, RENE JUST (1743-1822)

Hauy in 18or . The earlier name titanite, given by M . H . See also:

• KLAPROTH, HEINRICH JULIUS (1783-1835)
• KLAPROTH, MARTIN HEINRICH (1743-1817)

Klaproth in 1795, is also in See also:

• COMMON

common use . Twinning on the ortho-pinacoid is not uncommon . The See also:

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

colour is 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, yellow, 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 or See also:

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

black, and the lustre resinous to adamantine; crystals are transparent to opaque . The hardness is 51, and the specific gravity 3.5 . The refractive indices and the optic 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 vary considerably with the colour of the See also:

• LIGHT

light: the See also:

• DISPERSION
• DISPERSION (from Lat. dispergere, to scatter)

dispersion of the optic axes is inclined, and the interference figure seen in convergent light between crossed nicols is very characteristic of the mineral . Sphene is sometimes cut as a See also:

• GEM (Lat. gemma, a bud,—from the root gen, meaning " to produce,"—or precious stone; in the latter sense the Greek term is > d>os)
• GEM, ARTIFICIAL

gem-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, though it is rather too soft to stand much See also:

• WEAR

wear; owing to its high dispersive See also:

• POWER [WILLIAM GRATTAN] TYRONE (1797-1841)

power it gives brilliant flashes of prismatic See also:

• COLOURS, MILITARY

colours .

As small embedded crystals, sphene has a wide See also:

• DISTRIBUTION (Lat. distribuere, to deal out)

distribution as an See also:

• ACCESSORY

accessory constituent of many kinds of igneous rocks (See also:

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

granite, See also:

• SYENITE

syenite, See also:

• TRACHYTE (Gr. rpaxus, rough)

trachyte, See also:

• PHONOLITE (Gr. ~vi7, sound, and Moos, stone)

phonolite, &c.), and also of See also:

• GNEISS

gneiss, schist and crystalline See also:

• LIMESTONE

limestone . Sharply-See also:

• DEVELOPED

developed, transparent, 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 crystals are frequently associated with adularia, See also:

• ASBESTOS

asbestos and See also:

• QUARTZ

quartz in the crystal-lined crevices of the See also:

• SCHISTS (Gr. vxq'ecv, to split)

schists of the Swiss and Tyrolese See also:

• ALPS

Alps . Large, rough and dark-coloured crystals are found at See also:

• ARENDAL

Arendal and KragerS in See also:

• NORWAY
• NORWAY (Norge)

Norway, and in granular limestone at See also:

• DIANA

Diana in New See also:

• YORK
• YORK (HOUSE OF)
• YORK, EDMUND OF LANGLEY, DUKE OF (1341-1402)
• YORK, EDWARD
• YORK, FREDERICK AUGUSTUS, DUKE OF (1763-1827)
• YORK, RICHARD, DUKE

York and Eganville in See also:

• ONTARIO
• ONTARIO, LAKE

Ontario . A greyish, compact and impure' variety of spheric, known as " leucoxene," frequently occurs in basic igneous rocks as an alteration product of See also:

• ILMENITE

ilmenite and See also:

• RUTILE

rutile . (L . J .