Search the Dictionary

A rare element of the chromium group found in certain minerals, as wolfram and scheelite, and isolated as a heavy steel-gray metal which is very hard and infusible. It has both acid and basic properties. When alloyed in small quantities with steel, it greatly increases its hardness. Symbol W (Wolframium). Atomic weight…

The oxide of tungsten, a yellow mineral occurring in a pulverulent form. It is often associated with wolfram.

low powder, Hg3O2SO4, which consists of a basic mercuric sulphate; -- called also turpeth mineral.

Having a fine light blue color, like that of choice mineral turquoise.

A translucent mineral of a green color and pearly or vitreous luster. It is a hydrous arseniate of copper.

A mineral occurring in white rounded crystalline masses. It is a hydrous borate of lime and soda.

A brittle mineral of a steel-gray color and metallic luster, containing antimony, arsenic, sulphur, and nickel.

Having a smooth, greasy feel, as certain minerals.

A mineral consisting chiefly of uranium oxide with some lead, thorium, etc., occurring in black octahedrons, also in masses with a pitchlike luster; pitchblende.

An element of the chromium group, found in certain rare minerals, as pitchblende, uranite, etc., and reduced as a heavy, hard, nickel-white metal which is quite permanent. Its yellow oxide is used to impart to glass a delicate greenish-yellow tint which is accompanied by a strong fluorescence, and its black oxide is us…

ests; to usher a visitor into the room. The stars that usher evening rose. Milton. The Examiner was ushered into the world by a letter, setting forth the great genius of the author. Addison.

A mineral occurring in yellowish, and ruby-red hexagonal crystals. It consist of lead vanadate with a small proportion of lead chloride.

A rare element of the nitrogen-phosphorus group, found combined, in vanadates, in certain minerals, and reduced as an infusible, grayish-white metallic powder. It is intermediate between the metals and the non-metals, having both basic and acid properties. Sumbol V (or Vd, rarely). Atomic weight 51.2.…

An apple-green mineral occurring in reniform masses. It is a hydrous phosphate of alumina.

A wooden tub for washing ores and mineral substances in.

rresponding with the stratification; a lode; a dike; -- often limited, in the language of miners, to a mineral vein or lode, that is, to a vein which contains useful minerals or ores.

The nonmetalliferous mineral or rock material which accompanies the ores in a vein, as quartz, calcite, barite, fluor spar, etc.; -- called also veinstuff.

f lime, whiting, chalk, etc.) They consist of hydrated copper carbonates analogous to the minerals azurite and malachite. Verditer blue, a pale greenish blue color, like that of the pigment verditer.

A group of minerals having, a micaceous structure. They are hydrous silicates, derived generally from the alteration of some kind of mica. So called because the scales, when heated, open out into wormlike forms.

A bright red pigment consisting of mercuric sulphide, obtained either from the mineral cinnabar or artificially. It has a fine red color, and is much used in coloring sealing wax, in printing, etc.