ALLOPHANE.

Locality. Norway; principally in an ironmine near Drammen.

Name. From λños other, and xędía, colour; in_allusion to its variety of colours. Brit. Mus., Case 36.

ALLOGONITE, Breithaupt. See HERDE

RITE.

ALLOMORPHITE, Breithaupt. (From λ05, other, and uogo, form), A variety of Barytes found in scaly masses in Unterwirbach near Rudolstadt in Schwarzburg. According to Gerngross it contains 1.9 per cent. of sulphate of lime, as impurity.

ALLOPHANE. Occurs reniform, massive, encrusting; occasionally almost pulverulent. Colour pale blue, sometimes green, brown, yellow or colourless. Translucent. Lustre, vitreous or resinous; internally splendent and waxy. Streak white. Very brittle. Fracture flat conchoidal and shining. Adheres to the tongue. H. 3. S.G. 1.76 to 1.89. Comp. Hydrated silicate of alumina, or Ai3 Si2+15H.=silica 24-22, alumina 40-39, water 35.39=100.

Protoxide of cerium

Oxide of lanthanium

Yttria

Lime

Magnesia

Potash

wich:

Alumina

Analysis by A. B. Northcote, from Wool

BB on charcoal swells up, becomes brownish-yellow and fuses to a black (somewhat magnetic) glass.

Localities.-Scotch. 1 mile west of New Abbey, near Criffel, E. Kirkcudbrightshire; in syenite.-Foreign. Norway; at Naes Mine about 10 miles east of Arendal; Jotun Fjeld, in porphyry: Snarum, with Albite. Greenland, in granite. Plauensche Grund, near Dresden, in Saxony. Near Suhl in the Thuringerwald, in granite. Moriah, Essex co., New York, with Lanthanite, at the junction of the Sanford magnetic iron with the granite walls.

Name. After Thomas Allan, of Edinburgh, by whom it was first noticed as a distinct species.

Brit. Mus., Case 38. ALLEMONTITE. A name given to arsenical antimony, found at Allemont in Dauphiny. Analysis by Rammelsberg : Arsenic. Antimony

.62.15 . 37.85

100.00

ALLEY STONE. See WEBSTERITE. ALLOCHROITE, a fine-grained, massive variety of iron-Garnet of a greyish, dingy yellow, or reddish colour. Opaque. Fracture uneven. H. not so hard as Quartz, but strikes fire with steel. S.G. 3-7 to 4-21. BB behaves like Melanite.

Protoxide of iron
Lime.
Carbonic acid
Water

BB soon loses colour, and becomes pulverulent, causing some intumescence and tinging the flame green. Alone infusible; with borax fuses readily to a transparent colourless glass. Dissolves perfectly in dilute acids; when digested in concentrated acids, leaves a silicious jelly.

Localities. Allophane has been lately observed at the chalk-pits at New Charlton, near Woolwich, Kent, by the students of the Government School of Mines, and determined by them in the laboratory of Dr. Percy. It occurs abundantly, of a honey-yellow colour, in the chalk of Beauvais in France; also lining irregular cavities in a kind of marl at Saalfield in Thuringia, Schneeberg in Saxony, Visé in Belgium and elsewhere. At Richmond, Massachusetts, U.S., it occurs with Gibbsite, forming a hyaline crust, scaly or compact in structure, and brittle; also, at the Bristol copper mine, Connecticut, U.S.

Name. From λλos, other, and paiva, to appear; in allusion to its change of appearance under the blowpipe.

Brit. Mus., Case 26.

ALLOPHANE OPAL.

Allophane usually occurs lining small cavities, and in veins in marl or chalk; sometimes in little reniform masses with a resinous or waxy lustre.

ALLOPHANE OPAL. See SCHRÖTTERITE. ALLOY OF IRIDIUM AND OSMIUM, Wollaston, Phillips. See IRIDOSMINE.

ALLUAUDITE, Damour, Nicol. Occurs massive, with a triple cleavage at right angles to each other. Colour clove-brown. Subtranslucent or opaque. Lustre dull. Streak yellowish. Fracture scaly, shining. H. above 4. S.G. 3.468.

Comp. (Mn Na) +Ë Ï + H.

e

Analysis (mean of several) by Damour:
Phosphoric acid
Peroxide of iron

Protoxide of manganese
Peroxide of manganese

Soda

Silica. Water

.

41.25 25 62

23.08

1.06

5.47

0.60

2.65

99.73

BB on platina wire fuses to a black magnetic globule. Forms a solution in muriatic acid which is black when cold, and yellowish-brown when heated.

Locality. Chanteloupe, near Limoges in France, associated with Vivianite and Dufrénite.

Name. After Mons. Alluaud of Limoges. ALMAGRERITE, Breithaupt. An anhy drous sulphate of zinc occurring in crystals isomorphous with Anglesite and Heavy Spar, at the Barranca Jaroso Mine, in the Sierra Almagrera, Spain. S.G. 4:33.

ALMANDINE, or ALMANDINE GARNET, is the name given to red transparent varieties of Garnet. It is an alumina-iron Garnet, the composition of which is represented by the formula Fe Si+Al Sisilica 36·3, alumina 20.5, protoxide of iron 43.2=100. Cubical: occurs in rhombic dodecahedrons, and, in the same with all the edges replaced by sixsided planes. Lustre vitreous, shining. Streak white. Fracture subconchoidal, uneven. H. 6.5 to 7.5. S.G. 3-7 to 4.21.

Analysis by Hisinger, from Fahlun:
Silica

Alumina

Protoxide of iron.

Protoxide of manganese

39.66

19.66

39.68

1.80

100.80

BB fuses rather readily to a black magnetic globule with borax more slowly to a dark glass, affording an iron reaction. Insoluble in acid.

ALTAITE.

Localities. This stone is found in sand, alluvial soil, and gneiss, in Ceylon, Pegu, Hindostan, Brazil, Greenland; also at Elie in Fifeshire, at Ala in Piedmont, and in various parts of Bohemia.

When of good size, finely coloured, transparent, and free from flaws it is used as a gem. It should be cut quite thin on account of its depth of colour, with a pavilion on the under side and a broad table above, bordered with small facets. An octagonal Garnet, measuring 84 lines by 64, has sold for near 700 dollars. Almandine may be distinguished from Corundum or Spinel by its duller colour. Brit. Mus., Case 36.

M. P. G. Horse-shoe Case, Nos. 889 to 893, 897, 898.

ALMANDINE RUBY. The name given to violet-coloured varieties of Spinel.

ALMANDINE SPAR, Mohs. See EUDIA

BB decrepitates and phosphoresces. Dissolves in acids with effervescence.

Localities. Fallowfield, near Hexham, Northumberland; in small six-sided pyramidal crystals, of a pinkish tinge. Bromley Hill, near Alston (whence the name Alstonite) Cumberland; of a white or grey colour, in veins with Galena.

ALTAITE, Dana, Haidinger, Nicol. Cubical. Usually occurs massive in granular aggregates; rarely in cubes. Colour tin-white, with a yellow tarnish. Lustre metallic. Sectile. Fracture uneven. H. 3 to 3.5. S.G. 8:10.

10

Fig. 8.

ALVITE.

Fig. 9.

ALUMSTONE.

Analysis by G. Rose.

Lead

Tellurium

Silver.

100.

60.35 38.37 1.28

100.00

BB colours the flame blue: in the inner flame volatilizes, except a minute globule of silver. Soluble in nitric acid.

Locality. The Savodinsky mine, near Barnaoul, in the Altai; mixed with telluric silver.

ALVITE, David Forbes & F. Dahll. Crystallizes like Zircon. Colour reddish-brown, becoming greyish-brown on alteration. Opaque; translucent at the edges. Lustre greasy. Fracture conchoidal. H. 5'5. S.G. 3.40 to 3.6.

BB in the platina forceps infusible: becomes paler by heat. With borax yields a yellow glass, which becomes colourless on cooling.

Comp. An approximative analysis shows it to consist chiefly of silica, yttria, thorina(?), alumina, and glucina, peroxide of iron and

water.

Localities. Helle and Narestö in Norway. ALUM. Under this name are comprised several compounds which have the general formula R S + Al S3 +24 H, (R representing different bases, as potash, soda, magnesia, protoxide of manganese, &c.) which are described under their respective names. All these compounds crystallize in octahedrons, but they usually occur in nature in fibrous masses, or as a mealy efflorescence, with a sweetish astringent taste, more or less resembling that of common alum. It is soluble in from 16 to 20 times its weight of cold water, and in little more than its own weight of boiling water. On exposure to heat, it melts easily in its own water of crystallization, and froths up in a remarkable way, and by continuance of heat it is converted into a white spongy mass. Alum is used largely in the manufacture of leather and paper, as a mordant in dyeing, in medicine, for preserving animal substances from putrefaction, and for various other purposes. The alum of commerce is made either from clay or from alum-slate or shale. Much of

by evaporation. At Whitby, in Yorkshire, the alum-shale is mixed with fuel and set on fire; the residue is lixiviated with water, and purified by subsequent evaporation; potash salts are added, and crystallized alum is finally formed. The best alum is made from the Alum-stone of Tolfa, near Civita Vecchia. ALUM, Nicol, Phillips. Native alum. See POTASH-ALUM.

ALUMINE FLUATÉE ALCALINE, Haïy. See CRYOLITE.

ALUMINE FLUATÉE SILICEUSE, Haüy. See TOPAZ.

ALUMINE HYDRATÉE SILICIFÈRE, Levy. Siliciferous hydrate of alumina. ALUMINE - HYDRO-PHOSPHATÉE, Haüy. See WAvellite.

ALUMINE MAGNÉSIÉE, Haüy. See SPINEL. ALUMINE SOUS-SULFATÉE. See WEB

BB decrepitates and is infusible alone and with soda: with borax forms a colourless glass.

Soluble in sulphuric acid, when reduced to powder. Insoluble in water, but after gentle ignition, gives up alum to it, the excess of alumina remaining undissolved.

Localities. Tolfa, near Civita Vecchia, in the Papal States. Musay and Bereghszasz, in Hungary. Milo, Argentiera, in the Grecian Archipelago. The Island of Nevis. Pic de Sancy, in France. Elizabethpol, in Georgia. Silesia, in a coal-bed.

Much of the best alum of commerce is procured from Alumstone by repeated roastings, washings, and finally crystallizing by evaporation. Some of the Hungarian varieties are so hard and compact as to be used for millstones.

Brit. Mus., Case 55.

M. P. G. Upper gallery, table-case B, in recess 6, Nos. 179 to 186.

ALUN-AMMONIACAL, Dufrénoy. See AM

MONIA-ALUM.

ALUN DE PLUME, Dufrénoy. See HALO

TRICHITE.

ALUN DE ROME, the commercial name for alum made at Tolfa. See ALUM-STONE. ALUN-MAGNESIEN, Dufrénoy. See MAG

NESIA-ALUM.

ALUN SODIFÈRE, Dufrénoy. See SODA ALUM.

ALUNITE, Necker. See ALUMSTONE. ALUNOGENE, Beudant, Duna, is a hydrous sulphate of alumina, composed, when pure, of alumina 15-42, sulphuric acid 85-99, water 48-59 = 100.00, corresponding

to the formula Al 3+18 H. It occurs generally in delicate fibrous masses or crusts, either white or tinged with yellow or red, when impure. Translucent. Lustre silky. Taste like that of common alum. H. 1.5 to 2. S.G. 1.6 to 1.8.

BB intumesces and fuses easily. Very soluble.

Localities. It occurs at Araya near Cumana; Socono; Copiapo, in Chili, and other parts of South America; in numerous places in the United States; at Adelaide, in New South Wales, &c. &c.

Alunogen results from volcanic action,
and the decomposition of Pyrites in shales.
AMALGAM, Dana.
AMALGAME, Necker.

AMALGAME NATIF D'ARGENT,
La Metherie.

AMALGAME D'OR.

AMANSITE
AMANTICE

AMAUSITE, Dufrénoy
AMAUTITE
AMAUZITE

See NATIVE AMAL

GAM.

See ELECTRUM. A variety of compact Felspar (Orthoclase) from Edelfors in Sweden.

Colour clear grey passing into greyish-white. Fracture perfect conchoidal.

AMAZON STONE. A bluish-green variety of Felspar (Orthoclase). It is slightly translucent at the edges, and possesses a considerable amount of varying lustre. The stone brought from Lake Baikal in Siberia is sometimes, though rarely, in pieces sufficiently large to be made into small vases and other ornaments; and, when well cut, it forms an Aventurine composed of silvery spangles in a green base. The verdigrisgreen variety found on the east side of Lake Ilmen is coloured by copper.

Brit. Mus., Case 30.

M. P. G. Horse-shoe Case, No. 955.

AMBER is found in irregular masses of all shades of yellow, from the palest primrose to the deepest orange, sometimes brown. It is brittle, yields readily to the knife, affording a white streak, and breaks with a fracture which is more or less perfectly conchoidal. It varies from perfect transparency to complete opacity, sometimes, but rarely, being nearly as white as ivory, and has a vitreous or resinous lustre. H. 2 to 2.5 S.G. 1:08.

Comp. C10 H8 O=carbon 78 96, hydrogen 10:51, oxygen 10.52. Burns readily with a yellow flame, emitting an agreeable odour, and leaves a black, shining, light, carbonaceous residue. Becomes negatively electric by friction. Soluble in alcohol.

Considerable quantities of Amber are cast ashore during autumnal storms on the coasts of Pomerania and Prussia Proper, and are carefully collected. Amber is also found along the whole line of the Baltic coast, but the largest specimens are procured from the Prussian shores, and the search for it is an industry exercised from Dantzic to Memel. This is distinguished as marine Amber. The other description, called terrestial Amber, is dug in mines and is generally found in alluvial deposits of sand and clay, associated with fossil wood, Iron Pyrites, and alumshale. It is also found on the Sicilian coast, near Catania; at Hasen Island in Greenland; in clay at Auteuil, near Paris; but more plentifully in certain lignite deposits of the Aisne, and occasionally on the sea-coasts of Norfolk, Essex, Sussex, and Kent. It occurs in sand at Kensington, near London; in Ireland on the coast at Howth, near Dublin; at Craignashoke, in Ulster; and at Rathlin Island, Antrim. Amber, to a considerable amount, is also said to be taken to China from a northerly part of Upper Burmah.

The vegetable origin of Amber is now fully ascertained, by the experiments of Sir David Brewster on its optical properties, as well as from its association with coal, and lignite, and the occurrence in it of the remains of insects and plants. According to Goeppert, Amber is the mineralised resin of extinct Coniferæ, one of which he has named Pinites succinifer, or Amber-bearing Pinetree. The insects inclosed in it, which are mostly, if not all, of extinct species, appear to have been entangled in the then viscous substance while alive, and, in many cases, to have struggled hard to escape, as is evident from the legs and wings which are frequently found separated from the bodies to which they once belonged.

Yellow amber, cut in facets, or simply in beads for bracelets and necklaces, was long in fashion, and is sometimes worn at the present day. It is used in the East by Turks, Egyptians, Arabs, Persians, and the natives of India, to ornament their pipes, arms, the saddles and bridles of their horses, and even of their camels; and in the West it is made into beads, necklaces, brooches, earrings, boxes, and small works of art, canehandles, mouth-pieces of pipes, and occasionally into candlesticks, salvers, pipetubes, and other larger articles. Four amber mouth-pieces, set with brilliants, exhibited in the Turkish Section of the Great Exhibition of 1851 were valued together at £1,000. The estimation in which Amber is held in Turkey for the mouth-pieces of

AMBER.

pipes, may be in some measure accounted for by the current belief entertained in that country, where it is a great mark of politeness to offer the pipe to a stranger, that Amber is incapable of transmitting infection. The straw-yellow, slightly clouded, translucent variety is the rarest, and that preferred to all others by the Orientals, who purchase it at extravagant prices. In other countries the orange-yellow transparent variety is decidedly preferred.

"Sir Plume, of amber snuff-box justly vain, And the nice conduct of a clouded* cane:' POPE, Rape of the Lock.

In the Museum of Mineralogy in Paris there is the handle of a cane made of Amber, the colour of which is of so pure a yellow, and so limpid, that it might almost be mistaken for a Brazilian Topaz.

The principal use of Amber in the Arts is for obtaining, by distillation, succinic acid and oil of amber, which it affords at a low temperature, leaving an extremely black, shining residue, which is employed as the basis of the finest black varnishes.

Amber was known to the ancients, and made by them into various ornamental articles. It was said by the common fable to consist of the tears of those poplars into which Phaeton's sisters were transformed. Pliny says, because our ancestors believed that it was the juice of a tree (succum) they called it (in Latin) succinum. The Greeks called it "Hargov, (either from its resemblance in colour to the alloy of gold and silver of that name, or from 'Haixrag, a name of the sun), and whence, on account of its electrical properties, the derivation of the word electricity. By some of the ancients Amber was called Lyncurion, and believed to be produced from the urine of the lynx; from that of the males when of a deep and fiery tint; but when of a pale hue from that

* These clouded canes were made of fine

marbles, richly mounted with gold, silver, amber, &c. In the early part of the eighteenth century the most fashionable sorts of walking-sticks were made of certain fine marbles and agates, exhibiting either a splendid variety of colour, or a rich semi-opaque plain tint, which was most expressively described by the English term "clouded. These wands were made of the most slender pro

portions, both on account of their specific gravity, and the quality of the persons by whom they were to be carried; and they were often richly mounted with silver, gold, amber, or precious stones. Such were the "clouded canes" of the age of Pope and Gay, which were frequently so cases of greatly valued, as to be preserved in shagreen or sheaths of leather.-(See the Tatler No. 103, 6th December, 1709.)