444 



MINERALOGY. 



Oi-yctogno- hand into greyish-black, on the other into greyish- 

 .. _ _*y* _^ white, as also into greenish, greyish, and smoke-grey. 

 *"" It seldom occurs pure in the mineral kingdom. Ex- 

 amples, quartz, flint, mica, and zoisite. 

 /*. Steel-grey is dark ash-grey with metallic lustre. It 

 is the colour of newly broken steel. Examples, grey 

 copper and native platina. 



C. BLACK. 



It presents fewer varieties than any of the other colours, 

 owing probably to the intermixture of lighter colours 

 not being observable in it. The discrimination of its 

 varieties is attended with considerable difficulty, and 

 can only be satisfactorily accomplished after much 

 practice. The following are its varieties : 



a. Greyish-black is velvet-black mixed with ash-grey. 

 It passes into ash-grey. Is very distinct in basalt. 



b. Iron- black is principally distinguished from the pre- 

 ceding variety by its being rather darker, and pos- 

 sessing a metallic lustre. It passes into steel-grey. 

 Examples, magnetic iron-ore and iron-mica. 



c. Velvet-black is the characteristic colour of this series. 

 It is the colour of black velvet. Example, obsidian. 



d. Pilch-black, or brownish-black, is velvet-black mixed 

 with a little yellowish-brown. It passes into black, 

 ish-brown. Example, earthy cobalt ochre and mica. 



e. Greenish-black, or raven-black, is velvet-black mixed 

 with a little greenish-grey. It passes into black, 

 ish-green. Example, hornblende. 



f. Bluish-black is velvet-black mixed with a little blue. 

 It passes into blackish-blue, and appears sometimes 

 to contain a slight trace of red. Example, black 

 earthy cobalt-ochre. 



D. BLUE. 



The characteristic colour, which is Berlin-blue, is 

 placed in the middle of the series, and all those va- 

 rieties that contain red in their composition, on the 

 one side, and those containing green, on the other. 

 It is rarer among minerals than the preceding; 

 blackish blue connects it with black, sky-bJue with 

 green ; and it is connected with red by violet-blue 

 and azure-blue. The following are its varieties. 

 * a. Blackish-blue is Berlin-blue mixed with much black 

 and a trace of red. It passes, on the one side, into 

 bluish-black, on the other, into azure- blue. Exam- 

 ple, blue-copper, the dark varieties. 



b. Azure-bine is Berlin-blue mixed with a little red. It 

 is a burning colour. Examples, blue copper, and 

 azure-stone. 



c. Violet-blue is Berlin-blue mixed with much red and 

 very little black. It borders on columbine- red.- It 

 is the tint of colour we observe in the violet when 

 it is about to blow. It is the most frequent of the 

 blue colours. Examples, Amethyst and fluor-spar. 



curs in pale-coloured smalt, named eschel, also in Oryctogno- 

 earthy-blue iron, earthy blue copper, and in some *)' 

 varieties of gypsum. wy-^^ 



h. Duck-blue is a dark blue colour, composed of blue, 

 much green, and a little black. Frequently in cev- 

 lanite, and in a rare variety of indurated talc. 



i. Indigo-blue, a deep blue colour, composed of blue, 

 with a considerable portion of black and a little green. 

 Example, earthy blue iron of Eckardsberg in Thu- 

 ringia. 



k. Sky-blue is a pale blue colour, composed of blue, 

 green, and a little white. It forms the link which 

 connects the blue series with the green. It is named 

 mountain-blue by painters. It is the colour of a 

 clear sky, and hence its name. It occurs but rare- 

 ly in the mineral kingdom. Example, Lenticular 

 copper. 



E. GREEN. 



The varieties of this colour naturally fall into two 

 principal suites ; in the one of which the blue co- 

 lour prevails; in the other the yellow; and be- 

 tween the two is placed the pure or characteris- 

 tic colour, the emerald-green. Although, it is not 

 a common colour in the mineral kingdom, yet it is 

 met with more frequently than the blue. In earthy 

 minerals the green colours are generally owing to 

 oxide of iron; in a few cases to the oxide of 

 chrome ; in others to oxide of copper ; and in a 

 very few to oxide of nickel. 

 The following are the varieties of this colour. 



a. Verdigris- green is emerald green mixed with much 

 Berlin-blue, and a little white. It is the link which 

 connects the green and blue colours together. Ex- 

 amples, Copper-green and green Siberian felspar. 



b. Celandine green is verdigris-green mixed with ash- 

 grey. Examples, Green-earth, Siberian and Brazi- 

 lian beryl. 



c. Mountain- green is emerald green, mixed with much 

 blue, and a little yellowish-grey ; or verdigris green 

 with yellowish grey. It passes into greenish-grey. 

 Examples, Beryl, aqua marine topaz, glassy acty. 

 nolite, common garnet, and hornstone. 



d. Leek-green is emerald green, with bluish-grey and 

 a little brown. It is the sap-green of painters. In 

 this colour, the blue and yellow colours are in equal 

 proportions. Examples, Nephrite, common actyno- 

 lite, and prase. 



e. Emerald-green. The characteristic or pure unmix- 

 ed green. All the preceding green colours are more 

 or less mixed with blue, and at length pass into it ; 

 but the following part of the green series, by the 

 increasing proportion of yellow, at length passes 

 into yellow. Examples, Emerald, fibrous malachite, 

 copper-mica, and sometimes also fluor-spar. 



d. Lavender- blue is violet-blue, intermixed with a small f- Apple-green is emerald green mixed with a little 

 portion of grey. It is intermediate between pearl- greyish-white. It passes into greenish white. Ex. 

 grey and violet-blue. Examples, Lithomarge and 



porcelain-jasper. 



e. Plum-blue is Berlin-blue, with more red than in 

 violet-blue, and a small portion of brown and black. 

 It passes into cherry-red and broccoli-brown. Ex- 

 ample, Spinel. 



f. Berlin-blue is the purest or characteristic colour of 



the series. Example, Sapphire, rock-salt and kya- 



nite. 

 g. Smalt-blue is Berlin-blue with much white, and a 



trace of green. It passes into milk-white. It oc. 



3 



greyish-white. It passes into greenish white, 

 amples, Nickel ochre and chrysoprase. 



g. Grass-green is emerald green mixed with a little 

 lemon-yellow. The colour of fresh newly sprung 

 grass. Example, Uranite. 



h. Blackish-green is pistachio-green mixed with a con- 

 siderable portion of black. It passes into greenish. 

 black. Examples, Precious serpentine and augite. 



'. Pistachio green is emerald-green mixed with more 

 yellow than in grass-green, and a small portion of 

 brown. Examples, Chrysolite, and epidote or pista* 

 cite. 



