B. GREY.
This, which is one of the palest colours, is a compound of white and black, so that it forms the link by which these two colours are connected together, and is therefore placed between them. It occurs very fre quently in the mineral kingdom. The following arc 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.
a.. Whitish lead-grey. It is a very light lead-grey colour, into the composition of which a consider able portion of white enters, and nearly approaches to tin-white. Examples, native arsenic on the fresh fracture.
)3. Common lead-grey. It is the purest lead grey, with a slight intermixture of yellow. Examples, common grey antimony.
y. Fresh 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 lybdena.
.".`. Blackish lead-grey. Is common lead-grey mixed with a little black. Examples, silver-glance or sul phuretted silver, and copper-glance or vitreous cop per.
b. Bluish-grey is ash-grey mixed with a little blue, or is lead-grey without metallic lustre. Examples, horn stone 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 pearl.
d. Smoke-grey or brownish-grey, is dark bluish-grey mixed with a little brown. Examples, flint, and some varieties of fluor-spar.
e. Greenish-grey is ash-grey mixed with a little eme rald-green, and has sometimes a faint trace of yellow. It passes into mountain-f;rcen. Examples, clay-slate, whet-slate, potstone, sometimes mica, prehnite, and cat's-eye.
f Yellowish-grey is ash-grey mixed with lemon-yellow and a minute trace of brown. It sometimes passes into cream-yellow and wood-brown. Examples, cal
cerlony and mica.
g..4sh-grcy is the characteristic colour. It is a com pound of yellowish-u bite and brownish-black. It is the colour of woed-ashes. It passes on the one hand into greyish-black, on the other into greyish-white, as also into greenish, greyish, and smoke-grey. It sel dom occurs pure in the mineral kingdom. Exam amples, quartz, flint, mica, and zoisite.
h. Steel-grey is dark ash-grey with metallic lustre. It is the colour of newly broken steel. Examples, grey copper and native platina.
C. Br.vcx.
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 (hiker, and pos sessing a metallic lustre. It passes into steel-grey. Examples, magnetic iron-ore and lion-mica.
c. Velvet-black is the characteristic colour of this series. It is the colour of black velvet. Example, obsidian.
d. Pitch-black, or brownish-black, is velvet-black mixed with a little yellowish-blown. It passes into ish-brown. Example, earthy cobalt ochre and mica.
c. Greenish-black, or raven-black, is velvet-black mixed with a little greenish-grey. It passes into blackish 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.