MANCc^J^ESE DEPOSITS OF INDIA: ECONOMICS. [PaET III : 
black tints by the nse of tliis substance. According to Sir George Watti 
the colours in the Indian enamels are invariably due to borates and sihcates 
of the metals, manganese carbonate being used to produce violet. The 
pyrolusite of Gosalpur in the Jabalpur district is supposed to have 
been worked from ancient times for use by glass-workers as a colouring 
material. Watt2 gives an interesting account 
Use of manganese for gf the ornamentation of the pottery of Pesha- 
war. He says ; — 
pottery. 
' The pottery of this northern town has been spoken of as resembling majolica. 
It is a rough " faience". Ths reddish earth body or " paste " is coated with a dressing 
in white earth — the " slip ' or " engobe " which consists of a preparation of karia miiti 
or chalk, obtained from the Khaibar. It is then dipped into the glaze of which the 
basis is lead oxide. For the ordinary greenish white pottery, nothing else is needed. 
But when it is desired to ornament the plate or jar, the design is outlined on the un- 
burnt glaze, with a paint made of manganese, and the details are filled in with a 
preparation of copper. When burned, green leaves, outlined in brown, are produced 
on a dirty white. Sometimes the glaze is more thoroughly fused and the colours 
then run and the bro%vn takes a purplish tint. Further colours are red, obtained 
from a red earth, and black, from a stone of dark colour — both procured from the 
Khaibar. ' 
The dark ere last referred to may very well be an ore of manganese. 
At Raniganj, Messrs. Burn & Co. use manganese-ore to a small 
extent for imparting dark brown and black body colours to tiles and 
pottery, and also for imparting dark brown and black glazes to ordinary 
biscuit- ware. Formerly, inferior black tiles were produced without the 
use of manganese, the black colour being obtained by using disintegrated 
laterite with a Uttle salt — not enough to glaze — added at a high beat, 
a reducing atmosphere being maintained. But about 20 years ago the 
use of manganese -ore was begun with the production of a very superior 
black colour. 
The mixture used by Messrs. Burn & Co. in 1904 for producing black 
tiles is the following : — 
Parts by measure. 
Black biscuit 
Kankar 3 
Durgapur clay . 
Manganese- ore . 
Felspar , 
The material all passes a sieve of -10 holes to the hnear inch. 
3 
2 
2 
3 
2 
Bv using 
half the quantit} of manganese-ore, a chucolate-coloured tile is obt lined. 
1 ' Indian Art at Delhi '. p. 22, (1903). 
2 Loc. cil.. p. 89. 
8 Roally diisintegratod laterite. 
