Ores of Mercury. 107 SPECIES 2. Amalgam of filver *. Native amalgam. This mineral has been found in the filver mine of Amalgam Sahlbergt, in the province of Dalecarlia, in Sweden; of filver. in the mines of Deux Ponts, in the Palatinate; and *Kirwan, in other places. It is in thin plates, or grains, or cry. ii. 223. ftallized in cubes, parallelopipeds, or pyramids. + Cronfiedt's Min. Its colour is filvery white or grey. Luftre metal#Heyer. lic. Creaks when cut. Sp. gr. above 10. Tinges Grell's An- gold white. Before the blow-pipe the mercury evapomals, 1790. rates and leaves the filver. Beiträge, i. 183. 198 G. II. Sulphurers. Common fulphuret. * Kirtan, ii. 228. ↑ Romé de Life, iii. 2546 Hauy, Fear. de Min. No xxxi. p. 518. contained A fpecimen of this amalgam, analyfed by Klaproth, Sometimes it contains a mixture of alumina, and fometimes the proportion of mercury is fo great that the amalgam is nearly as foft as pafte. GENUS II. SULPHURETS OF MERCURY. This ore, which is found in almoft all mercurial mines, is fometimes in veins, fometimes diffeminated, fometimes in grains, and fometimes cryftallized. The form of its crystals is a tetrahedron or three-fided pyramid, moft commonly wanting the fummit; fometimes two of thefe pyramids are joined bafe to bafe; and fometimes there is a three-fided prism interpofed between them †. Its colour is red. Its ftreak red and metallic. Luftre when cryftallized 2 to 3; when amorphous, often o. Transparency, when cryftallized, from 1 to 3; when amorphous, often o. Texture generally foliated. Hardnefs from 3 to 8. Sp. gr. from 5.419 to 10.1285. Before the blow pipe evaporates with a blue flame and fulphureous fmell. Infoluble in nitric acid t. Variety 1. Dark red. Colour cochineal red. Hardness 6 to 7. Sp. gr. when pure, 10.1285 §; fometimes only 7.2, or even 6.188. Variety 2. Bright red. Colour commonly fcarlet. Sp. gr. 6.9022 † to Briffon. Mufcben broek. Briten. Gellert. 5.4191. 199 G. III. Oxyds. GENUS III. OXYDS OF MERCURY. SPECIES 1. Hepatic mercurial ore*. This ore, which is the moft common in the mines of Idria, is always amorphous, and is often mixed with namercurial tive mercury and cinnabar. Hepatic ore. *Kirwan, ii. 224. Its colour is fomewhat red. Its ftreak dark red and Hardness from brighter. Luftre commonly metallic. + Briffon. 6 to 8. Sp. gr. from 9.2301 to 7.186. When Kirwan. heated the mercury evaporates. Sage, four, de Phyf. xxiv. 6L. Scopoli, Jour. de Min. No xxxvi. p. 919 Though this ore has never been accurately analyfed, chemifts have concluded that the mercury which it contains is in the ftate of a red oxyd, because it is infoluble in nitric and foluble in muriatic acid q. When pureft, it contains about .77 of mercury. It contains alfo fome fulphur and iron. Werner has divided this fpecies into two varieties, the compact and the flaty. The fecond is often nothing more than bituminous fhale impregnated with oxyd of Kirwan, mercury t. ii. 226. This ore, which occurs in the Palatinate, is fome Mercurial times in fcales, fometimes in grains, and sometimes cry. ftallized. Its cryals are either fmall four or fix fided Muriat of prisms whofe fides are rhombs†, or cubes, or four-fided pyramids wanting their angles. They are always very ii. 226. fmall and generally confufed. Its colours are various; but it is most frequently white. Its luftre, when white, is pearly. Sometimes t opaque, and fometimes femitransparent. Evaporates before the blow pipe. Native copper occurs now and then in the greater per. number of copper mines: Sometimes it is in maffes, Kirwan, fometimes in plates and threads, which affume a variety of forms; and fometimes, as in Siberia, it is cryftallized + Hauy, in cubes, or other forms nearly refembling cubes t. Colour commonly that of copper, but fometimes dark Min N brown. Luftre metallic. Streak brighter. Fracture hackly. Flexible and malleable. Hardness 6 to 7. Sp. gr. from 7.6 to 8.5844¶. Copper calls compa&, from its fracture; and the fecond, for the fame reafon, he calls foliated. This laft is fomewhat darker coloured than the firft, but in other refpects they agree. Ores. 205 Copper pyrites. *Kirwan, ii. 140. Brion. || Id. 206 Purple copper ore. SPECIES 2. Copper pyrites*. Yelloro copper ore. This ore, which is probably nothing elfe than ful phuret of iron combined with copper, and which, there fore, would be more properly placed among iron ores, is found frequently in copper mines, and mixed with common pyrites er fulphuret of iron. It is fometimes amorphous, and fometimes crystallized. Its cryftals are either three or four fided pyramids applied bafe to bafe, or fix-fited plates. Its colour is yellow; often tarnifhed. Its internal luftre metallic. Hardness 6 to 7; sometimes 9. Brittle. Sp. gr. 4314† to 4.081. Deflagrates; but does not detonate with nitre ||. Before the blow-pipe decrepitates, gives a greenish fulphureous fmoke, and melts into a black mafs, which tinges borax green. Does not effervefce with nitric acid, SPECIES 3. Purple copper ore *. This ore is found in maffes, or plates, or diffemina *Kirwan, ted; fometimes, alfo, it is cryftallized in octohedrons. Colour various, but moft commonly purple; internally reddish. Streak reddish and bright. Luftre metallic. → Ibid. ii. Hardness 6 to 7. Brittle. Sp. gr. 4.956 to 4.983† Effervefces with nitric acid, and tinges it green. Deflagrates with nitre. Before the blow-pipe melts readily, without fmoke, vapour, or smell; but is not reduced. Tinges borax a bright green. ii. 142. 243. Beiträge, ii. 286. A fpecimen of this ore, analyfed by Klaproth, contained 58 copper, 18 iron, 19 fulphur, 5 oxygen. 100 + SPECIES 4. Grey copper ore §. 207 Grey cop- This ore is found in Cornwal, Saxony, Hungary, per ore. Kirwan, &c. It is often amorphous, but often alfo cryftallized. The primitive form of its cryftals is the regular tetrahedron, but, in general, either the angles or the edges, or both, are truncated or bevelled ||. ji. 146. Romé de Liste, iii. 315. Hauy, Four.de Min. No zxxi. 512. Colour feel grey; often tarnished, and then dark grey. Streak dark grey; fometimes reddish brown. Powder blackifh; fometimes with a tint of red. Luftre metallic Hardness 7 or 8. Very brittle. Sp. gr. 4.8648. Deflagrates with nitre. Before the blowpipe crackles, but at laft melts, especially if affifted by borax. The bead gives a white fmoke, without any particular fmell; tinges borax yellow or brownish red, but does not unite with it. A fpecimen of this ore from Cremnitz, analyfed by Klaproth, contained Colour commonly cochineal red. Streak brick red. Four, de Luftre femimetallic. Transparency, when amorphous, Min. Ne generally o; when cryftallized, 3 or 4. Hardnefs from xxi. 517 4 to 7. Soluble with effervefcence in nitric acid. Before the blow-pipe melts easily, and is reduced. This ore was fuppofed to be compofed of carbonic acid and red oxyd of copper; but a fpecimen, exami ned by Vauquelin, which confifted of pure cryftals, contained no acid †. It must therefore be contidered as an Ibide oxyd of copper. Werner has made three varieties of this ore, which, from their texture, he has denominated compact, foliated, and fibrous. The firft is feldom or never found cryftallized, and is opaque; the fecond occurs amorphous, cryftallized, and in fcales; the third is carmine, ruby, or fcarlet red; and occurs always in fhort capillary cryfals, or delicate flakes. This ore fometimes contains a mixture of red oxyd of iron; it is then called brick red copper ore, copper malm, or copper ochre. This ore, which was brought from Peru by Dombey, When thrown on burning coals, it communicates a is a grafs green powder, mixed with grains of quartz. 149. green colour to the flame. It is foluble both in nitric and muriatic acids without effervescence. The folution is green. It was fuppofed to contain muriatic acid *;* Bertbollsha but Vauquelin has difcovered, that the appearance of Mem. Par. this acid was owing to the prefence of fome common 1786, 462. falt, which is accidentally mixed with the sand ‡. This ore, which occurs in the copper mines of Sibe-nat of cop ria, Sweden, Germany, Hungary, Cornwal, &c. is ei-per. ther amorphous or cryftallized. The cryftals are fmall, and difficult to examine. According to Romé de Lifle, their primitive form is an octohedron, the fides of which are ifofceles triangles, and two of them more inclined than the others. Be that as it may, the cryftals of Crystal. blue carbonat of copper are often rhomboidal prifms, 343 either regular, or terminated by dihedral fummits *. * Ibid. P. Its colour is azure or smalt blue. Streak blue. Hard-, 345 (D) Kirw. II. 129.-Morveau, Mem. Dijon, 1782. 1 Semestre, p. 100. nefs $ Cooper nefs 4 to 6. Brittle. Sp. gr. 3.608 t. It effervefces with nitric acid, and gives it a blue colour. Before the blow-pipe it blackens, but does not melt. Tinges borax green with effervescences. Ores. Briffon. 211 Green carbonat of copper. The cryftals, according to Pelletier, are composed of 66 to 70 copper, +8 20 carbonic acid, 8 2- 2 water. Fontana first difcovered that this ore contained carbonic acid gas. Variety 1. Earthy blue carbonat. This variety generally contains a mixture of lime. It is never cryftallized; and fometimes is almost in the ftate of powder. Luftre o. Texture earthy. Variety 2. Striated blue carbonat of copper. Luftre glaffy. Transparency, when cryftallized, 2; when amorphous, 1. Texture ftriated; fometimes approaching to the foliated. SPECIES 2. Green carbonat of copper (E). Oxygenated carbonat of copper-Malachite. This ore is generally amorphous, but fometimes it is cryftallized in four-fided prifms, terminated by fourfided pyramids. Colour green. Luftre filky. Hardnefs 5 to 7. Briffon. Brittle. Effervefces Sp. gr. 3.571* to 3.653 . Kirwan, with nitric acid, and gives a blue colour to ammonia. Before the blow pipe it decrepitates and blackens, but does not melt. Tinges borax yellowish green. It is composed of carbonic acid and green oxyd of iron. Variety 1. Fibrous malachite. Texture fibrous. Opaque when amorphous; when crystallized its tranfpatency is 2. Colour generally grafs green. Variety 2. Compact malachite. Texture compact. Opaque. Colour varies from the dark emerald green to blackish green. A fpecimen of malachite from Siberia, analysed by Klaproth, contained 58.0 copper, 18.0 carbonic acid, 125 oxygen, 11.5 water. Ores. || Klaproth's tions on fometimes olive green. Luftre glaffy. Tranfparency Metallic from 4 to 2. Fracture conchoidal. Hardnefs 4 to 7. Before the blow-pipe deflagrates with an arfenical smoke, and melts into a grey coloured bead. This bead, fufed with borax, leaves a button of pure copper ||. Klaproth discovered that it was compofed of oxyd of Obfervacopper and arfenic acid. Sometimes this ore is combined with iron. It then p. 29. cryftallizes in cubes. Thefe cubes are of a dark green colour; before the blow-pipe they frothe, give out an arfenical fmoke, and do not fo quickly form as the arfeniat of copper Native iron has been found in Siberia and in Peru iron. in immense masses, which feemed as if they had been fufed. These maffes evidently did not originate in the place where they were found. See FIRE-Balls, Suppl. Colour bluish white. Fracture hackly. Luftre metallic. Malleable. Magnetic. Hardness 8 to 9. Sp. gr. 7.8. Prouft has difcovered, that the native iron found in Peru is alloyed with nickel ¶. GENUS II SULPHURETS OF IRON. Nicholfon's four. iii. 374 216 G. III. Sul iron. This mineral occurs very frequently both in ores and phurets. mixed with other bodies, for inftance in flates. It is Common often amorphous, and often also cryftallized. The pri- fulphuret of mitive form of its cryftals is either a regular cube or an Kirwan, octobedron. The varieties of its form hitherto defcri- ii. 76.bed amount to 30; for a description of which we refer Henkel's Pythe reader to Romé de Life +. ritologia. Its colour is yellow. Its luftre metallic. Hardnefs Craftul. 8 to 10. Brittle. Sp. gr. 3.44 to 4.6. Soluble in nitric acid with effervefcence. Searce foluble in fulphuric acid. Before the blow-pipe burns with a blue flame and a fulphureous fmell, and leaves a brownish bead, which tinges borax of a fmutty green. Variety 1. Common pyrites. Fracture uneven Hardnefs 10. Decrepitates when heated. Emits a fulphureous smell when rubbed. Not magnetic. It occurs often in coal mines and in flates. Variety 2. Striated pyrites. Texture ftriated. Hardnefs 10. Not magnetic. Variety 3. Capillary. Colour often feel grey. Found in needle-form cryftals. Uncommon. Not magnetic. Variety 4. Magnetic pyrites. Found in maffes. Texture compact. Hardness 8, 9. Slightly magnetic. Seems to contain lefs fulphur than the other varieties. In pyrites the proportion of the fulphur to the ion is variable, and this explains the variety of its cryftalline forms. (E) Kirw. II. 131.-Fontana, Jour. de Phyf. XI. 509.—Klaproth, Beiträge, II. 287. GENUS iii. 208. (F) Pallas, Phil. Tranf. LXVI. 523.—Rubin de Celis, ibid. LXXVIII. 37.-See allo Schreiber, Jour. de Phyf. XLI. 3.; and Stelin, Phil. Tranf. LXIV. 461. Iron Ores. 217 G. II. Plun.bago. ii. 58. GENUS III. CARBURET OF IRON. SPECIES I. Plumbago *: This mineral is found in England, Germany, France, Kirwan, Spain, America, &c. It occurs in kidney form lumps of various fizes. Its colour is dark iron grey or brown ish black; when cut, bluish grey. Lustre metallic, from 3 to 4. Opaque. Structure flaty. Texture fine grained. Hardness 4 to 5. Brittle. Sp. gr. from 1.987 to 2.089; after being foaked in water 2.15; after being heated 2.3, and when heated after that Brion. 2.41t. Feels fomewhat greafy. Stains the fingers, and marks ftrongly. The use of thie mineral when manufactured into pencils is known to every perfon. Its compofition was discovered by Scheele. When pure it contains 90 carbon, Jour. de Min. No zii. p. 16. 218 G. IV. Emery. *Kirwan, 10 iron. ii. 193. large maffes. Its colour is bluish grey, greyish brown, or bluish black, often covered with a yellowish rind; internally it difcovers red or purple fpots. Luftre 1 or o; in Brisson. Come parts 2, and metallic. Opaque. Hardnefs 14. Brittle. Sp. gr. 3.92t. Before the blow pipe it blackens and gives a fmutty yellow tinge to borax. According to Wiegleb it contains 95.6 filica, 4 3 iron. 219 G. V. Oxyds. 220 Black oxy of iron. Kirwan, ii. 158. 99.9 GENUS V. OXYDS OF IRON. This genus is very extensive; for iron is much more frequently found in the ftate of an oxyd than in any other. SPECIES 1. Black oxyd of iron ‡. Common magnetic iron flone-Blackifh octohedral iron ore. This fpecies of ore is very common in Sweden; it is found alio in Switzerland, Norway, Ruffia, &c. It occurs in maffes, plates, grains, and cryftallized. The primitive form of its cryftals is a regular octohedron t. Sometimes two oppofite fides of the pyramids are trapeziums, which renders the apex of the pyramids cuneiform. Sometimes the cryftals pafs into rhomboidal pa. rallelopipeds, and into dodecahedrons with 1homboidal Min. No faces §. xxxiii. 659. Romé de Lifle, iii. 178. $ Ibid. Hauy, Four. de Min. ii. grey. Its furface is brownish black; internally bluish + Kirwan's Powder black *. Streak blackish grey, brighter. Luttre metallic. Harduefs 9 to 10. Brittle. Sp. gr. fron 4 004 to 4.688+. Attracted by the magnet, and ge nerally poffeffed of more or lefs magnetic virtue‡. 159. Hauy, Four de Min. No xxxi. 527. Ores. this fpecies belongs the magnet. Before the blow-pipe Metallic it becomes browner, but does not melt. Tinges boraz dark green. When pure it confifts entirely of oxyd of iron; and this oxyd appears to contain from .15 to 24 oxygen, and from .76 to .85 iron f. Undoubtedly it confifts King of a mixture of iron in two different ftates of oxyda. Min. it tion. It is often alfo mixed and contaminated with '59. foreign ingredients. There are two varieties of this ore. The first is what we have just described; the fecond is in the form of sand, and has therefore been called Magnetic fand *. * Kirwan, No This fubftance is found in Italy, Virginia, St Do--Dapu. mingo, the East Indies, and in the fand of the river Dons, r at Aberdeen in Scotland. It is black, very hard, mag-xxi. p. 75.. netic. Sp. gr. about 4.6. Not altered by the blowSp. pipe per fe; melts into a black glafs with potafs, and It probably contains fome filica, as Kirwan has fup-4. into a green glafs with microcofmic falt, both opaquet.+ Fourcroy, pofed t. SPECIES 2. Specular iron ore ¶. This ore is found abundantly in the ifle of Elba near Specular Tufcany. It is either in maffes or cryftallized. The iron ore. primitive form of its cryftals, and of its integrant mole-¶ Kirw i cules, is the cube *. The varieties hitherto obferved a-162-Ca drai, Jour mount to 7. These are the rhomboidal parallelopiped; de Phyf. iv. the cube, with three triangular faces inftead of two of 52. its angles diagonally oppofite; two fix-fided pyramids, Hawy, applied bafe to bafe, wanting the fummits ‡, and fome. Jour. de times the angles at the bales, and fometimes the alter-xxxii. 660. nate edges of the pyramid; a polyhedron of 24 fides, Fig. 39. refembling a cube with three triangular faces for two angles diagonally oppofite, and two triangles for the reit of its angles. For a defcription and figure of these varieties, we refer to Romé de Liflet and Hauy‡. + Cryf.. Colour fteel grey; often tarnished, and beautifully 189. Streak red. iridescent, reflecting yellow, blue, red. Powder dark red. Luftre metallic. Hardness 9 to 10. Not brittle. Sp. gr. 5.0116+ to 5.218. Slightly + Hay magnetic. Little altered by the blow pipe. Tinges brig blow-pipe. borax an obfcure yellow. This ore, according to Mr Mufhet, is compofed of 664 iron, Is generally confidered as a variety of this fpecies. Kirwan, however, fuppofes it to contain carbon, and to be a diftinét fpecies. It is found in Saxony, and in the ile of Elba, &c. generally in amorphous maffes, compofed of thin fixfided lamine. Colour iron grey. Streak bluish grey. Luftre metallic. Opaque. Feel greafy. Hardness 5 Toto 7. Brittle. Sp. gr. from 4.5 to 5.07. Slightly magnetic. Ibed 665 + Philof 354. Ores. Iron Ores magnetic. Infufible by the blow-pipe. Tinges borax to 5.005. Before the blow pipe blackens, but does Metallic greenish brown. not melt. Tinges borax yellowish olive When green. digefted in ammonia, it becomes black and often magnetic. 222 Laminated specular iron orc. SPECIES 3. Laminated fpecular iron ore. Fer pyrocete of Hauy. This ore, which is found at Montd'or in Auvergn, was ufually arranged under the laft fpecies; but has been feparated from it, we think properly, by Mr Hauy, because the form of its cryftals is incompatible with the fuppofition that their primitive nucleus is a cube, as we have feen is the cafe with common fpecular iron ore. Its cryftals are thin octagonal plates, bounded by fix linear +De Life, trapeziums, alternately inclined different wayst. Colour fteel grey. iii. 188. ‡ Hauy, Jour. de Min. No xxxi. 33. 223 Brown iron ore. Kirw. ii. 163. + Gellert. Kirwan. Kirwan's Min. ii. 164. + Brijon. Kirwan 224 Red iron Powder reddish black. Luftre metallic; furface polifhed. Fracture glaffy. Very brittle . Hauy fuppofes that this ore has been produced by fire, and accordingly has given it a name which denotes its origin. SPECIES 4. Brown iron ore ¶. This fpecies of ore is found abundantly in Britain, particularly in Cumberland and Lancafhire; and it is alfo very common in other counties. It confifts of the brown oxyd of iron, more or lefs contaminated with other ingredients. Found fometimes in powder, fometimes indurated. Variety 1. Brown hæmatites. The name hæmatites (bloodstone) was probably applied by the ancients only to thofe ores which are of a red colour, and have some resemblance to clotted blood; but by the moderns it is applied to all the ores of iron which give a reddish coloured powder, provided they be of a fibrous texture. Brown hæmatites occurs in maffes of various fhapes, and it is faid also to have been found cryftallized in five or fix fided acute angled pyramids. Colour of the furface brown or black, fometimes iridescent; internally nut brown. Powder red. Texture fibrous. Hardnefs 8 to 10. Brittle. Sp. gr. 3.789† to 3.951‡. Not magnetic. This variety has not been analyfed, but it feems to confift of brown oxyd of iron, oxyd of manganefe, and ཤ. alumina Variety 2. Compa& brown iron stone. This variety occurs in males of very various and often fantastical fhapes. Colour brown. Internal luftre metallic. Texture compact. Hardnefs 6 to 9. Brittle. Sp. gr. 3.4771t to 3.551. Variety 3. Brown Scaly iron ore. This variety is generally incumbent on other mine rals. Colour brown. Luftre metallic. Stains the fingers, marks frongly. Feels unctuous. Texture fɔliated. Hardness 3 to 5. Brittle. So light as often to float on water. Variety 4. Brown iron ochre. This variety occurs both maffive and diffeminated. Colour from nut brown to orange. Luftre o. Strongly ftains the fingers. Texture earthy. Hardness 3 to 4. When flightly heated reddens. -re. Kirw. ii. 68. Colour most commonly dark brown. Streak red or yellowish brown. Sp. gr. from 2 673 to 3.471. Bet Kirwan. fore the blow-pipe blackens, and tinges borax olive green and blackih. It is compofed of oxyd of iron, alumina, lime, filica in various proportions. It generally yields from 30 to 40 per cent. of iron. Variety 1. Common argillaceous iron ore. The minerals arranged under this variety differ confiderably from each other in their external characters: They are found in maises of various fhapes, and often form large ftrata. Colour various fhades of grey, brown, yellow, and red. Streak reddifh yellow or dark red. Luftre o. Hardnefs from 3 to 8. Smell earthy when breathed upon. Variety 2. Columnar or fcapiform iron ore. This variety is found in columns, adhering to each other, but cafily feparable: They are commonly incurvated, and their furface is rough. Colour brownish red. Streek dark red. Slightly ftains the fingers. Luftre Adheres ftrongly to the tongue. Sound hollow. Feel dry. Texture earthy. O. Variety 3. Acinofe iron ore. This variety is found in maffes, and is commonly len. ticular. Colour generally brownifh red. Luftre metallic, nearly. Texture granular. Hardness 5 to 9. Brittle. Variety |