THORITE  , a rare See also:

• MINERAL

mineral consisting of See also:

• THORIUM (symbol Th, atomic weight ,232.42 [0=16])

thorium silicate, crystallizing in the tetragonal See also:

• SYSTEM

system and isomorphous with See also:

• ZIRCON

zircon . The theoretical See also:

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

formula, ThSiO4, requires 81.5 % of thoria, but analyses show only 50-70%, there being also some See also:

• URANIUM [symbol U, atomic weight 238.5 (0=16)]

uranium, See also:

• CERIUM (symbol Ce, atomic weight 140.25)

cerium, &c . The mineral is almost always altered by hydration and is then optically isotropic and amorphous . Owing to See also:

• DIFFERENCES, CALCULUS OF (Theory of Finite Differences)

differences in See also:

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

composition and to alteration, the specific gravity varies from 4.4 to 5.4 . The See also:

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

colour is usually See also:

• LIGHT

light 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, but in the variety known as " orangite " it is See also:

• ORANGE
• ORANGE (Citrus Aurantium)
• ORANGE, HOUSE OF

orange-yellow . The mineral occurs as isolated crystals and small masses in the See also:

• AUGITE

augite-See also:

• SYENITE

syenite near Brevik in See also:

• SOUTH
• SOUTH, ROBERT (1634–1716)

South See also:

• NORWAY
• NORWAY (Norge)

Norway; also at See also:

• ARENDAL

Arendal, and in the 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-gravels of See also:

• CEYLON

Ceylon . If found in larger amount it would be an important source of thoria for incandescent See also:

• GAS

gas mantles . (L . J .