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SPINEL , a name now given to a See also:group of minerals, of which the typical member is a See also:magnesium aluminate, sometimes used as a See also:gem-See also:- STONE
- STONE (0. Eng. shin; the word is common to Teutonic languages, cf. Ger. Stein, Du. steen, Dan. and Swed. sten; the root is also seen in Gr. aria, pebble)
- STONE, CHARLES POMEROY (1824-1887)
- STONE, EDWARD JAMES (1831-1897)
- STONE, FRANK (1800-1859)
- STONE, GEORGE (1708—1764)
- STONE, LUCY [BLACKWELL] (1818-1893)
- STONE, MARCUS (184o— )
- STONE, NICHOLAS (1586-1647)
stone, to which the See also:term " spinel " was originally restricted. The name comes from the See also:French spindle (diminutive of See also:Lat. See also:spina), perhaps suggested by the See also:sharp angles of the crystals. All spinels crystallize in the cubic See also:system, usually in octahedra, and often twinned as in the accompanying figure, which is a See also:form so characteristic as to be called the "spinel twin." The hardness of spinel is about that of See also:topaz (8) and its specific gravity near that of See also:diamond. See also:Professor A. H. See also:- CHURCH
- CHURCH (according to most authorities derived from the Gr. Kvpcaxov [&wµa], " the Lord's [house]," and common to many Teutonic, Slavonic and other languages under various forms—Scottish kirk, Ger. Kirche, Swed. kirka, Dan. kirke, Russ. tserkov, Buig. cerk
- CHURCH, FREDERICK EDWIN (1826-1900)
- CHURCH, GEORGE EARL (1835–1910)
- CHURCH, RICHARD WILLIAM (1815–189o)
- CHURCH, SIR RICHARD (1784–1873)
Church gives the range in variously coloured spinels as 3.582 to. 3.715. Pure spinel is colourless, but most varieties are coloured, no doubt in many cases with See also:iron and probably in some with See also:chromium. The deep red spinel is known
as " spinel-See also:ruby," or " ruby-spinel," and has often been taken for true ruby, from which it is distinguished, however, by being singly refracting and therefore not 'dichroic, as well as by its inferior hardness and See also:density. The " balas ruby " is a See also:rose-red spinel, said to derive its name from See also:Balkh, the See also:capital of See also:Badakshan (Balaxia), where it occurs with rubies, and was formerly worked, chiefly in the Shighnan valley, in the upper See also:Oxus See also:basin. Rubicelle is a spinel in which the red See also:colour tends to See also:orange, whilst in See also:almandine-spinel it passes into See also:violet. Stones of the colour of See also:vinegar are called vinegarspinel. When the colour is See also:blue the See also:mineral is known as See also:sapphire-spinel, and when See also:green as chloro-spinel.
The spinels used in See also:jewelry are found mostly in gem-gravels, where, however, the octahedral form is often well preserved. The See also:chief localities are See also:Ceylon, See also:Siam and Upper See also:Burma. In all these localities the spinels accompany the coloured corundums, and their See also:close association with true rubies led See also:Tavernier to See also:call spinel " the See also:mother of ruby." Formerly there was much confusion between the two minerals, and probably many stones described as See also:monster rubies have been spinels. The See also:great historic " ruby" set in the Maltese See also:cross in front of the Imperial See also:state See also:crown of See also:England is really a spinel. This See also:fine stone was given to See also:Edward the See also:Black See also:Prince by Pedro the Cruel, See also:- KING
- KING (O. Eng. cyning, abbreviated into cyng, cing; cf. O. H. G. chun- kuning, chun- kunig, M.H.G. kiinic, kiinec, kiinc, Mod. Ger. Konig, O. Norse konungr, kongr, Swed. konung, kung)
- KING [OF OCKHAM], PETER KING, 1ST BARON (1669-1734)
- KING, CHARLES WILLIAM (1818-1888)
- KING, CLARENCE (1842–1901)
- KING, EDWARD (1612–1637)
- KING, EDWARD (1829–1910)
- KING, HENRY (1591-1669)
- KING, RUFUS (1755–1827)
- KING, THOMAS (1730–1805)
- KING, WILLIAM (1650-1729)
- KING, WILLIAM (1663–1712)
king of See also:Castile, on the victory of Najera in 1367, and it was afterwards worn by See also:- HENRY
- HENRY (1129-1195)
- HENRY (c. 1108-1139)
- HENRY (c. 1174–1216)
- HENRY (Fr. Henri; Span. Enrique; Ger. Heinrich; Mid. H. Ger. Heinrich and Heimrich; O.H.G. Haimi- or Heimirih, i.e. " prince, or chief of the house," from O.H.G. heim, the Eng. home, and rih, Goth. reiks; compare Lat. rex " king "—" rich," therefore " mig
- HENRY, EDWARD LAMSON (1841– )
- HENRY, JAMES (1798-1876)
- HENRY, JOSEPH (1797-1878)
- HENRY, MATTHEW (1662-1714)
- HENRY, PATRICK (1736–1799)
- HENRY, PRINCE OF BATTENBERG (1858-1896)
- HENRY, ROBERT (1718-1790)
- HENRY, VICTOR (1850– )
- HENRY, WILLIAM (1795-1836)
Henry V. at the See also:battle of See also:Agincourt, when it narrowly escaped destruction. V. See also:Ball described, in 1894, a spinel weighing 1331 carats, engraved with a See also:Persian inscription, then in the See also:possession of See also:Lady See also:Carew.
All the isomorphous minerals known as the group of spinellids, of which spinel is the type, crystallize in See also:regular octahedra and have a See also:composition conforming to the See also:general See also:formula R"Ra"'Os ( R"O• See also:R2" Oa). See also:Ordinary spinel is MgAl3O4. A black opaque See also:spinet in which Fe partly replaces Mg is known as pleonaste (,raeovaoros, abundant, from the number of faces on certain crystals) or ceylonite, from the See also:island of Ceylon, but sometimes written ceylanite. It occurs in See also:gneiss, often with cordierite, and is found also in the ejected blocks of See also:Monte Somma, See also:Vesuvius. Large crystals come from See also:Warwick and Amity, Orange See also:county, New See also:York, U.S.A. The black spinels are generally green or See also:- BROWN
- BROWN, CHARLES BROCKDEN (1771-181o)
- BROWN, FORD MADOX (1821-1893)
- BROWN, FRANCIS (1849- )
- BROWN, GEORGE (1818-188o)
- BROWN, HENRY KIRKE (1814-1886)
- BROWN, JACOB (1775–1828)
- BROWN, JOHN (1715–1766)
- BROWN, JOHN (1722-1787)
- BROWN, JOHN (1735–1788)
- BROWN, JOHN (1784–1858)
- BROWN, JOHN (1800-1859)
- BROWN, JOHN (1810—1882)
- BROWN, JOHN GEORGE (1831— )
- BROWN, ROBERT (1773-1858)
- BROWN, SAMUEL MORISON (1817—1856)
- BROWN, SIR GEORGE (1790-1865)
- BROWN, SIR JOHN (1816-1896)
- BROWN, SIR WILLIAM, BART
- BROWN, THOMAS (1663-1704)
- BROWN, THOMAS (1778-1820)
- BROWN, THOMAS EDWARD (1830-1897)
- BROWN, WILLIAM LAURENCE (1755–1830)
brown when viewed in thin sections by transmitted See also:light. In some cases spinel is evidently a result of contact See also:metamorphism, whilst in others it has crystallized out of a molten magma, as illustrated by the experiments of J. Morozewicz. A chrome-spinel with the formula (Mg,Fe) (Al,Fe,Cr)2Os is named picotite, after Picot de la Peyrouse, who described it. Picotite occurs in the form of black grains and crystals in certain See also:olivine rocks and in See also:serpentine. A black iron-spinel (FeAI20s),
found in the granulites of See also:Saxony and Bohemia, is known as hercynite from the Hercynian See also:Forest. A See also:zinc-spinel (ZnAl2O4), occurring in talcose See also:slate near See also:Falun in See also:Sweden, is named gahnite, after its discoverer J. G. Gahn; whilst it has also been termed automolite from Gr. aoroµoXos, a deserter, in allusion to the occurrence of zinc in a mineral where it was unexpected. The group of spinellids includes, as its extreme members, See also:magnetite (Fe"See also:Fez"'O4) and See also:chromite (FeCr2O4) (q.v.). (F. W.
End of Article: SPINEL
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