MINERALOGY. 



443 



r- 



Arrange 



met.: ' 



Orjetogno- yellow ; 3d, From names used by painters, as indigo- 

 blue, verdigris-green, and azure-blue; 4th, From that 

 colour in the composition which is next in quantity to 

 the principal colour, as bluish-grey, yellowish-brown, 

 &c. ; and, 5th, From the names of persons, as Isabella- 

 yellow, now called cream-yellow. 



The principal colours are divided into two series, the 

 one comprehending what Werner terms bright colours, 

 the other dead colours ; red, green, blue, and yellow, 

 belong to the first; and white, grey, black, and brown, 

 to the second. They may also be divided into common 

 colourt, as emerald-green, &c. ; and into metallic co 

 lour*, as gold-yellow, &c. The metallic colours are 

 the most important as characters in describing mine- 

 rals. 



Arrangement of the Colourt. The different charac- 

 teristic colours and their varieties paw into each other, 

 UM colours. f ormm g gu ites of greater or less extent, in which the 

 colours either differ more and more from the firt mem- 

 ber of the series, a* they approach the extremity, thus 

 forming ttraight *eriet, or, after reaching a certain 

 point of greatest difference from the first colour, again 

 gradually approach, and at length pasa into it ; thus 

 on<ng circular tenet. In this way the eight princi- 

 pal colours pass into each other in the order in which 

 we have already enumerated them, and thus form a 

 straight series. The blue colour, however, after it bat 

 paard through green and yellow into red, passes 

 from this latter colour by several intermediate varie- 

 ties again into blue, thus forming a circular series or 

 group. 



In the system of colourt, wt do not introduce these 

 various subordinate transitions and series, but simply 

 arrange all the colourt as they pass into each other, 

 beginning with the white, and ending with the brown. 

 The varieties of mo*t of the different principal colours 

 are so arranged, that their characteristic colour is pla- 

 ced in the middle of the series, and all those varieties 

 that incline to the preceding principal colour are pla- 

 ced immediately alter it ; while those that incline to 

 the next or following principal colour immediately pre- 

 cede it I ln, however, is not the case with the white 

 and grey colours ; therefore the characteristic colours 

 in those series do not stand in the middle ; on the con- 

 trary, in the white it is placed at the beginning, and in 

 the grey at the end. 



I. Dffiailiom of the different Varietia of Colour. 



Dcftnitkmi A. WHITE. 



of the Mif- This is the lightest of all the colourt ; hence the ilight- 

 frtnt * est intermixture of other colours becomes perceptible. 

 The white colour occurs principally in earthy and 

 saline mineral*, seldom in metalliferous minerals, and 

 very rarely among* inflammable minerals. The lol- 

 lowing are the varieties of this colour : 

 a. S*- ii-n'liile it the purest white colour, being free 

 of all intermixture, and it the only colour of this 

 suite which has no groy mixed with it. It resembles 

 new-fallen snow. As example* of it, we may men- 

 tion Carrara marble. 



t>. Reitduk mkilt is composed of snow-white, with a 

 very minute portion of crimson-red and ash-grey. 

 It p.i.e into flesh-red. Examples, porcelain earth 

 ami ro*e-qiiarta. 



c. Yflloiruh mhitt is composed of snow-white, with 

 very little lemon-yellow and ash-grey. It passes on 

 the one side into yellowish-grey, on the other into 



straw-yellow. Examples, chalk, limestone, and semi- Oryctogn*. 

 opal. *J- 



d. Silver-white is the colour of native silver, and is dis- "~~v~ 

 tinguished from the preceding by its metallic lustre. 

 Examples, arsenical pyrites and native silver 



e. Greyish- while is snow-white mixed with a little ash- 

 grey. Examples, quarts and limestone. 



f. Greenith-trhUe is snow-white mixed with a very little 

 emerald -green and ash-grey. It passes into apple- 

 green. Examples, amianthus, foliated limestone, and 

 amethvst. 



;.'. Mslk-nhile is snow-white mixed with a little Berlin- 

 blue and ash-grey. It passes into smalt-blue. The 

 colour of skimmed milk. Examples, calcedony and 

 common opal. 



h. Tiit-n-hite differs from the preceding colour princi- 

 pally in containing a little more grey, and having 

 the metallic lustre. It passes into pale lead-grey. 

 Examples, native antimony and native mercury . 



B. GREV. 



Thi-, which is one of the palest colours, is a compound 

 of white ami black, so that it forms the link by which 

 these two colours are connected together, and it 

 therefore placed between them. It occurs very fre- 

 quently in the mineral kingdom. The following are 

 its varieties: 



a. Lead-grey is composed of light ash-grey with a small 

 portion of blue, and possesses metallic lustre. It 

 contains the following subordinate varieties. 

 . II Inlii/i lead-grey. It is a very light lead-grey 

 colour, into the composition of which a consider- 

 able portion of white enter*, and nearly approaches 

 to tin-white. Examples, native arsenic on the 

 fresh fracture. 



ft. Common lead-grey. It is the purest lead- grey, 

 with a slight intermixture of yellow. Examples, 

 common grey antimony. 



y. Freth lead-grey. It contains rather more blue 

 than the preceding variety, with a slight tint of 

 red, so that it has what is called a fresh or burning 

 aspect. Examples, galena or lead-glance, and mo- 

 lylnlena. 



). HlacLiih lead-grey. Is common lead-grey mixed 

 with a little black. Examples, silver-glance or 

 sulphuretted silver, and copper-glance or vitreous 

 copper. 



b. lUuuk-grey it ash-grey mixed with a little blue, or 

 is lead-grey without metallic lustre. Examples, 

 hornstone and limestone. 



c. Pearl grey is pale bluish-grey intermixed with a little 

 red. It passes into lavender-blue. Examples, quartz, 

 porcelain jasper, crystallized hornstone, and a very 

 pale variety of ptarl. 



d. Smoke-grey or bronmiih-grey it dark bluish-grey 

 mixed with a little brown. Examples, flint, and 

 some varieties of fluor-spar. 



c. (<rtrnu/i grry is ash-grey mixed with a little eme- 

 rald-green, and has sometimes a faint trace of yellow. 

 It pastes into mountain-green. Examples, clay-slate, 

 whet-slate, potstone, sometime! mica, prehnite, and 

 cat'sreye. 



f. Yclloii ish-grry is ash-grey mixed with lemon-yellow 

 and a minute trace of brown. It sometimes passe* 

 into cream-yellow and wood-brown. Examples, cal- 

 cedony and mica. 



g. Ash-grey is the characteristic colour. It it a com- 

 pound of yellowish-white and brownish-black. It 

 is the colour of wood-ashes. It passes on the one 



