MINERALOGY. 



Rhomboid=8l*.S3'- Cleavage same, or = r. H=2. 

 Sp. er.= 1.9, 2.0. 



Description. Colours emerald, apple, nd verdigris 

 green, and sometimes grass-green : on exposure to the 

 weather, it becomes trmw.yellow, cream-yellow, ochre- 

 yellow, and yellowish-brown. Occurs pulverulent, 

 massive, disseminated, stalactitic, tuberose, botryoidal, 

 reniform, in fibrous distinct concretions, and crystal- 

 lized. Shining, both externally and internally, and the 

 lustre is vitreou?, with exception of the fibrous varieties, 

 which are pearly. Fracture fiat conchoidal. Alternates 

 from semi-transparent to opaque. Refracts double. 



Chemical Character. Before the blowpipe, on char- 

 coal, it becomes magnetic, and colours glass of borax 

 green. 



Constituent Part*.- Oxide of iron 25.7 



Sulphuric acid -J-'i 



Water 45 4 -100 



Berzelim. 



CfOgnottic and Geograrhic Si'uatinns. It is always 

 associated with iron pyrite, by the decomposition of 

 which it is formed. Occurs in several coal mines in 

 this country, and in many iron and coal mine* on the 

 continent of Europe, and also in America and Asia 



v. It ii emp'oyed to dye linen yellow, and wool 

 and -ilk black ; in the preparation of ink ; of Berlin- 

 blue ; for the precipitation of gold from its solution ; 

 and sulphuric arid can be obtained from it bv distilla- 

 tion. The residue of the latter process (colcothar of 

 iron ) if used as a red paint, and, when wiuhed, for po- 

 lishing steel, 



Blu Viiri- * PKIMATIC VITRIOL, or BLUE VITRIOL, Ja:ntMon. 

 el. Prinmatisclitv. Vitriol-Salz, MoMt. Kupfervitriol, Wer- 



ner. 



Pri*m=l242'. Cleavage the tame. Hardnessr: 

 2.5. Sp. gravity =2.1. 2. 



internal Ckararifr*. Common colour dark sky- 



blue, which sometime* approaches to verdigris- green. 



By exposure to the air it become* yellow. It oc- 



m.Mve, d inseminated, utalacti'ic, dentiform, and 



illized. Externally and internally it is shin- 



ing and vitreous. The' fracture is conchoidal. 'I he 



fragments are rather sharp-edu'ed. It is Iran-lucent 



Ckrmical Ckarnelm. When a portion of it is dis- 

 solved in water, and spread on the suface of iron, it 

 immediately cover* it with a film of co| 



ConUitvent 1'arlt. Oxide of Copper 3 i. \ S 

 Sulphuric Acid 31.57 

 Water . 36.30 100.00 



Cmtlit. Partt. 



. 



Geofnrulic and Geographic Silva'inni. It occurs, 

 along with copper pyrite>. in Pary'smine in Anglesea ; 

 and also in the copper-mines in the county of Wicklow 

 in reland. 



U*tt. It is used in cotton and linen printing; and 

 the oxide separated from it is used by painters. 



3. PYRAMIDAL VITRIOL, or WHITK VITRIOL, Jamtttm. 



White Vi. Pyramid = 120 90'. Cleavage unknown. Hardness= 



l '- rj '- grn\ it\ z:S. 



mlrrt Colon ri grey ish , yellowish, red- 

 disli, and greenish white. It occurs massive, stalactitic, 

 reniform, botryoidal. in cruets ; also in radiated, fibrous 

 and granular distinct concretions ; and crystallized It 

 is shining, translucent, brittle, and easily frangible. 



Chrm>cal(.haractrr* It intumesces before the blow- 

 pipe, but does not phosphoresce : it dissolves in 2.285 

 parts of boiling water. 



From lUmmelberg. 

 Oxide of Zinc 27-5 



Oxide of Manganese 0.5 

 Sulphuric Acid 22.01 

 Water 56.0 



477 



Ditto. Oryctogno. 

 21.739 y- 

 6.522 > Y " 



71.739 



100.0 100 



Klaproth, Beit. b. v. s. 196. Herz. Archiv. 



b. iii. s. 537. 



Geognottic and Geographic Situation*. It occurs in 

 repositories that contain blende, and appears to be form- 

 ed by the decomposition of that mineral. It occurs at 

 Holy well in Flintshire ; and it is said also in Cornwall. 

 Utet It is used as a medicine; is employed in 

 great quantities by varnishers to make oil drying ; and 

 a fine white colour named Zuic-trh/te, which is more 

 durable than white-lead, is prepared from it. To pre- 

 pare this colour, the salt is dissolved in water, and the 

 white oxide, which is the zinc- white, is precipitated 

 from it by means of potash or chalk. 



RED VITRIOL, or SULPHATE OF coe.\i.T,Jameion. 

 Kobaltvitriol, /JVrner. 



External Chtractrri. Colour flesh-red, inclining to j 

 rose-red. Occurs coralloidal, stalactitic, in crust> ; also O l. 

 in granular distinct concretions. Surface rough, and 

 longitudinally furrowed. Dull, and seldom shining on 

 the surfaces of the distinct concretions, and the lustre is 

 pearly. Fracture earthy. Fragments blunt-edged. 

 Opaque. A fiords a yellowish-white streak. Easily 

 friable, and brittle. Taste styptic. 



Chemical Character*., Its solution afford*, with car- 

 bonate of potash, a pale-bluish precipitate, which tinges 

 borax of a pure blue colour. 



Constituent Partt. Oxide of Cobalt 38 71 

 Sulphuric Acid l<)7t 

 Water 41.55100.00 



Koppe,\a Journal fur die Chemie, Physik et 

 r.ilogie, b. vi. Heft 1, 1808, i. 157. 



Gengnotlic and (lengrai)hic f>iluatintis. [t occurs in 

 mining-heap* in Biber, along with lamellar heavy-spar, 

 earthy cobalt, and grey cobalt ; and it has been also 

 found in the Leogang ut Salzburg. 



GENUS VII. SAL AMMONIAC. 

 Many axe*. Cleavage tessular. Taste sharp and _ 

 urinous. Ilardness=1.5 2. sp. gravity 1.5. 1.6. AMMO- 



Ml AC. 



1. OCTAHEDRAL SAL AMMONIAC, Jameinn. Oc- 

 taedrisches Salraiac Sabs, Mohs. Natiirlicher Salmiack, 



. . . ' 



niac. 

 Tessular. Cleavage octahedral. 



'1 In-, species is divided into two subspecies, viz. Vol- 

 canic sal ammoniac, and conchoidal sal ammoniac. 



FIRST SUBSPECIES. 



VOLCANIC SAL AMMONIAC, ,/amefon. Vulcanischer 

 Salmiak, Kartlen. Volcanic 



External Characters. Colours yellowish and greyish- Sjl Ammo- 

 white ; pearl-grey and smoke-grey ; wine-yellow ; mac ' 

 sometime^ apple-green, sulphur-yellow, and brownish- 

 black. Occurs in efflorescences, crust*, stalactitic. small 

 botryoidal, tuberose, corroded, al-o in granular concre- 

 tions, and crystallized figures. Crystal* small and very 

 small ; and lateral planes usually smooth. Externally 

 dull or glistening ; internally shining and vitreous. 

 Alternates from transparent and opaque. Slightly due- 

 tile and elastic. 



Chimicat Character*. When moistened, and rubbed 

 with quicklime, it gives out a pungent ammoniacal 

 odour. 



. 

 ()ctahedl 



