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MILLERITE

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Originally appearing in Volume V18, Page 466 of the 1911 Encyclopedia Britannica.
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MILLERITE , a See also:

mineral consisting of See also:nickel sulphide, NiS. Crystals belong to the See also:rhombohedral See also:system and have the See also:form of slender needles arranged in divergent See also:groups or of delicate See also:fibres loosely matted together. The See also:colour is See also:brass-yellow and the lustre metallic. Before the chemical See also:composition of the mineral had been determined it had been known as " capillary See also:pyrites " or " See also:hair pyrites " (Ger., Haarkies), and was not distinguished from the capillary forms of pyrites and See also:marcasite: the name millerite was given by W. See also:Haidinger in 1845, in See also:honour of W. H. See also:Miller. The hardness is 3–31 and the specific gravity 5.65. There are perfect cleavages parallel to the faces of the rhombohedron (too); and gliding planes parallel to the faces of the rhombohedron (11o), on which secondary twinning may be readily produced artificially by pressure. Typical specimens of millerite are found in the See also:coal See also:measures in the neighbourhood of Merthyr Tydvil in See also:South See also:Wales, where the delicate needles and fibres occur with crystals of See also:quartz and See also:pearl-spar in the fissures of septarian nodules of See also:clay-ironstone. Radiating groups of needles are found with See also:ankerite in cavities in See also:haematite in the See also:Sterling. mine at See also:Antwerp in See also:Jefferson See also:county, New See also:York. At the See also:Gap mine in See also:Lancaster county, See also:Pennsylvania, the mineral occurs as fibrous encrusting masses with a velvety lustre.

The most perfect crystals are those formerly found with See also:

calcite, See also:diopside and a See also:bright See also:green chrome-See also:garnet in a nickel mine at See also:Orford in See also:Sherbrooke county, See also:Quebec. (L. J. S.) MILLER'S THUMB (Coitus gobio), a small See also:fish, abundant in all See also:rivers and lakes of See also:northern and central See also:Europe with clear See also:water and gravelly bottom. The genus Coitus, to which the miller's thumb belongs, is easily recognized by its broad, See also:flat See also:head, rounded and scaleless See also:body, large See also:pectoral and narrow ventral fins, with two dorsal fins, the anterior shorter than the posterior; the praeoperculum is armed with a See also:simple or branched spine. The See also:species of the genus Coitus are rather numerous, and are confined to the See also:north temperate See also:zone of the globe, the See also:majority being marine, and known by the name of " bullheads." The miller's thumb is confined to fresh water; and only one other See also:freshwater species is found in Europe, C. poecilopus, from rivers of See also:Hungary, See also:Galicia, and the See also:Pyrenees; some others occur in the fresh See also:waters of northern See also:Asia and North See also:America. The miller's thumb is See also:common in all suitable localities in See also:Great See also:Britain, but is extremely rare in See also:Ireland; in the See also:Alps it reaches to an See also:altitude exceeding 7000 ft. Its usual length is from 3 to 5 in. Generally hidden under a See also:stone or in a hollow of the See also:bank, it watches for its See also:prey, which consists of small aquatic animals, and darts when disturbed with extra-See also:ordinary rapidity to some other See also:place of See also:refuge. The See also:female deposits her ova in a cavity under a stone, whilst the male watches and defends them until the See also:young are hatched and able to shift for themselves.

End of Article: MILLERITE

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