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A similar oxide, having a slight alkaline reaction, as lime, magnesia, strontia, baryta.

lization; often fibrous and massive; color grayish white or greenish. It is a silicate of magnesia with some iron. Bronzite is a ferriferous variety.

Sulphate of magnesia having cathartic qualities; -- originally prepared by boiling down the mineral waters at Epsom, England, -- whence the name; afterwards prepared from sea water; but now from certain minerals, as from siliceous hydrate of magnesia.

Native sulphate of magnesia or Epsom salt.

An amorphous mineral of apple-green color; a hydrous silicate of nickel and magnesia. It is an important ore of nickel.

A hydrous silicate of magnesia.

treous brown color, found in the ejected masses of Vesuvius. It is a silicate of iron and magnesia, containing fluorine.

A hydrous carbonate of magnesia occurring in white, early, amorphous masses.

red. (a) A purplish red earth or pigment composed of a silicate of iron and alumina, with magnesia. It comes from the Persian Gulf. Called also Persian red. (b) See Almagra. -- Indian rice (Bot.), a reedlike water grass. See Rice. -- Indian shot (Bot.), a plant of the genus Canna (C. Indica). The hard black seeds are…

A silicate of alumina, iron, and magnesia, having a bright blue color and vitreous luster; cordierite. It is remarkable for its dichroism, and is also called dichroite.

Hydrous sulphate of magnesia found at the salt mines of Stassfurt, Prussian Saxony.

ll masses, or in monoclinic crystals; blue spar. It is a hydrous phosphate of alumina and magnesia.

or carbonate of lime. It sometimes contains also magnesium carbonate, and is then called magnesian or dolomitic limestone. Crystalline limestone is called marble.

A borate of iron and magnesia, occurring in fibrous masses of a blackish green color.

le, quite permanent in dry air but tarnishing in moist air. It burns, forming (the oxide) magnesia, with the production of a blinding light (the so-called magnesium light) which is used in signaling, in pyrotechny, or in photography where a strong actinic illuminant is required. Its compounds occur abundantly, as in do…

soft, and light enough when in dry masses to float in water. It is a hydrous silicate of magnesia, and is obtained chiefly in Asia Minor. It is manufacturd into tobacco pipes, cigar holders, etc. Also called sepiolite.

A grayish or dark green mineral, consisting essentially of magnesia (magnesium oxide), occurring in granular forms or in isometric crystals.

ar bronze-red or copperlike color and a pearly luster. It is a silicate of aluminia, with magnesia, potash, and some fluorine. It is characteristic of crystalline limestone or dolomite and serpentine. See Mica.

An apple-green mineral having a greasy feel. It is a hydrous silicate of nickel, magnesia, aluminia, and iron.

brick-red color, being tinged with iron, and consisting chiefly of the sulphates of lime, magnesia, and soda.