Online Encyclopedia


Online Encyclopedia
Originally appearing in Volume V28, Page 759 of the 1911 Encyclopedia Britannica.
Spread the word: it!
WITHERITE, a mineral consisting of barium carbonate (BaCO3), crystallizing in the orthorhombic system. The crystals are invariably twinned together in groups of three, giving rise to pseudo-hexagonal forms somewhat resembling bipyramidal crystals of quartz, the faces are usually rough and striated horizontally. The colour is dull 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 barytes. It occurs in veins of lead ore at Hexham in Northumberland, Alston in Cumberland, Anglezark, near Chorley in Lancashire, and a few other localities. Witherite is readily altered to barium sulphate by the action of water containing calcium sulphate in solution, and crystals are therefore frequently encrusted with barytes. It is the chief source of barium salts, and is mined in considerable amounts in Northumberland. It is used for the preparation of rat poison, in the manufacture of glass and porcelain, and formerly for refining sugar. (L. J. S.)
End of Article: WITHERITE
GEORGE WITHER (1588-1667)

Additional information and Comments

There are no comments yet for this article.
» Add information or comments to this article.
Please link directly to this article:
Highlight the code below, right click and select "copy." Paste it into a website, email, or other HTML document.