MALACHITE 525 



Malacliite of the finest quality suitable for onmniental purposes occurs as nodular 

 masses often of considerable size, the surface of which may be rounded, reniform, botryoidal, 

 or stalactitic. These nodules have a radially fibrous structure, and are built up of concentric 

 shells. The external I'ounded surface is often blackish and dull, but fractured surfaces are 

 always green in colour, and show a slight silkiness of lustre owing to the fibrous structure of 

 the nnneral. The green colour of such a fractured surface is not quite uniform, and narrow 

 bands, alternately ligliter and darker, are often to be seen following the external outlines of 

 the stone, in the same manner as in agate. The presence of these bands together ^vith the 

 nbrous structure gives the stone a kind of grained appearance, which is often very effective 

 tor decorative purposes. A nodule of malachite in its natural condition is represented in 

 Plate XX., Fig. 4a, while Fig. 46, of the same plate, shows a polished slab of the same 

 material. 



The physical characters of malachite nuist now receive our attention. Owing to the 

 large amount of copper present the specific gravity is high; values ranging from 3-5 to 4-0' 

 have been given for different specimens, but the mean value is usually between 37 and 3-8. 

 The hardness is only about 3J, so that malachite is scratched even by fluor-spar. Being 

 opaque the liability to become scratched is not as serious a disadvantage as it would be in 

 the c^e of a transparent stone, but ne-\-ertheless it is advisable to protect malachite 

 ornaments as far as possible from injury in this direction. Because of the softness of this 

 mineral it is impossible to obtain a very strong lustre on a cut surface, although the 

 polish is decidedly good. Malachite is not brittle, and can therefore be worked on 

 the lathe. 



Malachite is a widely distributed mineral, but generally occurs in small masses only, 

 intergrown with other copper minerals. These impure masses are not suitable for cutting, 

 but they form at many localities not unimportant ores of copjjer. The wide distribution of 

 malachite is explained by the fact that other cupriferous minerals and ores — copper-pyrites, 

 cuprite, &c. — are readily altered to malachite ; in fact, the mineral always originates in this 

 way. Although malachite of inferior quality is abundant at many localities, large masses 

 of pure material suitable for ornamental purposes are by no means common. 



The largest amount of malachite suitable for cutting has been foimd in the Ural 

 Mountains, where also the largest and purest masses of material hitherto found have been 

 met with. In a sense, therefore, malachite is a Russian mineral, for in no other country 

 is it found in such abundance. The Urals are \ery rich in copper, but only a few of the 

 deposits are of importance from our present point of view, the majority yielding only 

 material fit for smelting. Malachite suitable for cutting has been obtained from the copper 

 mines at Nizhni-Tagilsk, at Bogoslovsk in the northern part of the mountains, and at 

 Gumeshevsk further to the south. At the beginning of the nineteenth century there was a 

 considerable yield of material suitable for cutting ; this has gradually fallen off, until at the 

 present day stones of this description are obtained only from the Medno-Rudiansk mine, 

 near Nizhni-Tagilsk, the other mines being exhausted or yielding impure material only. 

 The malachite usually occurs in nest-like masses in veins in limestone, from which it must 

 be extracted by the ordinary operations of mining. I^'he material, which is not sold in the 

 market in the rough condition, is cut in the lapidary works at Ekaterinburg. 



The mines which formerly yielded the finest material in the greatest abundance were 

 those of Gumeshevsk, situated fifty-six versts south-east of Ekaterinburg and very near the 

 58th meridian of longitude east of Paris, in the district of the Chussovaya. Reniform, 

 stalactitic, and tube-shaped masses of malachite, of various sizes and of a quality never seen 

 elsewhere, were found in these mines embedded in red clay. The larger of these masses 



