WITHERITE  , a See also:

• MINERAL

mineral consisting of See also:

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

barium carbonate (BaCO3), crystallizing in the orthorhombic See also:

• SYSTEM

system . The crystals are invariably twinned together in See also:

• GROUPS
• GROUPS, THEORY

groups of three, giving rise to pseudo-hexagonal forms somewhat resembling See also:

• BIPYRAMIDAL

bipyramidal crystals of See also:

• QUARTZ

quartz, the faces are usually rough and striated horizontally . The See also:

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

colour is dull 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 sometimes greyish, the hardness is 32 and the specific gravity 4.3 . The mineral is named after W . Withering, who in 1784 recognized it to be chemically distinct from See also:

• BARYTES

barytes . It occurs in See also:

• VEINS

veins of See also:

• LEAD
• LEAD (pronounced iced)

lead ore at See also:

• HEXHAM

Hexham in See also:

• NORTHUMBERLAND
• NORTHUMBERLAND, EARLS AND DUKES OF
• NORTHUMBERLAND, JOHN DUDLEY, VISCOUNT LISLE, EARL OF WARWICK
• NORTHUMBERLAND, JOHN NEVILLE, EARL OF (c. 1430-1471)

Northumberland, See also:

• ALSTON
• ALSTON, CHARLES (1683-176o)

Alston in See also:

• CUMBERLAND
• CUMBERLAND, DUKES AND EARLS OF
• CUMBERLAND, RICHARD (1632-1718)
• CUMBERLAND, RICHARD (1732-1811)
• CUMBERLAND, WILLIAM AUGUSTUS

Cumberland, Anglezark, near See also:

• CHORLEY
• CHORLEY, HENRY FOTHERGILL (1808—1872)

Chorley in See also:

• LANCASHIRE

Lancashire, and a few other localities . Witherite is readily altered to barium sulphate by the See also:

• ACTION

action of See also:

• WATER

water containing See also:

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

calcium sulphate in See also:

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

solution, and crystals are therefore frequently encrusted with barytes . It is the See also:

• CHIEF (from Fr. chef, head, Lat. caput)

chief source of barium salts, and is See also:

• MINED

mined in considerable amounts in Northumberland . It is used for the preparation of See also:

• RAT (a word common to Teut. and Rom. languages; probably first adopted in Teut.; the ultimate origin is not known; Skeat suggests the root rad-, to scratch; cf. Ger. Ratte, Dan. rotte, Fr. rat, &c.)

rat See also:

• POISON

poison, in the manufacture of See also:

• GLASS
• GLASS (O.E. glees, cf. Ger. Glas, perhaps derived from an old Teutonic root gla-, a variant of glo-, having the general sense of shining, cf. " glare," " glow ")
• GLASS, STAINED

glass and See also:

• PORCELAIN

porcelain, and formerly for refining See also:

• SUGAR

sugar . (L . J .