Minerals and Metals in Ancient India v1.c12.s6: Copper, Bronze and Other Metals
Minerals and Metals in Ancient India v1.c12.s6
- Language
- English
Copper, Bronze and Other Metals
v1.c12.s6.1
As in Mohenjo-Daro, a good number of copper objects have been found at Harappa. Amongst them the most noteworthy is a two-wheeled copper chariot, the kind of which has not been found elsewhere. Apart from this there were copper antimony rod stopper, copper mace-head and other copper beads, ornaments etc. But the most important discovery of metallic antiquities that has so far been made at this site is a large hoard of copper and bronze implement and other objects of daily use. Sana Ullah after analysing 16 samples has given the tabulated results (*vide* Table 4.1).
v1.c12.s6.2
From the Table 4.1 it is to be noted that these objects contain generally an appreciable, and sometimes considerable proportions of arsenic besides a small amount of nickel. Lead is either absent or much below 1 per cent, but specimens with higher proportions are met with occassionally. In the 48 Indus Valley specimens which have been analysed so far, these elements are distributed in the following manner:
v1.c12.s6.3
| | Per cent | Per cent |
| *Arsenic* | 0-.3 in 19 | .3-.5 in 5; |
| | .5-1.0 in 10; | 1-2 in 7 |
| | 2-7 in 7; | |
v1.c12.s6.4
| *Nickel* | 0-0.2 in 22; | 0.2-0.5 in 18 |
| | .5-1.0 in 6; | 1.0-1.5 in 2 |
| *Lead* | Nil in 15; | 0-0.5 in 14; |
| | .5-1 in 12; | 1-3 in 4; |
| | Above 3 in 2 | 32 in 1 |
v1.c12.s6.5
From the above table it will be seen that nickel is generally below .5 per cent and seldom exceeds 1 per cent, but the proportion of arsenic is relatively higher and sometimes excessive. The Sumerian copper also contains similar proportions of nickel, but it can be distinguished from the Indus Valley metal by its virtual freedom from arsenic. Arsenic-rich materials might have been deliberately added in Harappa copper.
v1.c12.s6.6
About the source of copper we have already discussed in the previous chapter. The Rajputana mines are nearest to Harappa and contain As and Ni; the extensive remains of ancient workings and heaps of slag in some of these mines indicate the existence of a flourishing copper industry in early India. Vats thinks that the small amount of tin, arsenic, antimony, lead, nickel and iron which have been found in the specimens of copper from Harappa imply impurities derived from the ores and not intentional addition for any specific purpose. However all these foreign elements influence the working properties of copper in varying degrees and add to its hardness or strength.
v1.c12.s6.7
The extent to which tin was mixed with copper in the various grades of bronze in use at Harappa and Mohenjo-Daro is apparent from the analysis of 48 specimens in which the percentage of tin was found to be as follows:
v1.c12.s6.8
| | *Per cent* | *Per cent* |
| *Tin* | 0-1 in 28; | 1-4 in 3; |
| | 4-8 in 7; | 8-11 in 6: |
| | 11-14 in 4 | |
v1.c12.s6.9
About the source of tin, discussion has already been made in the previous chapter.
v1.c12.s6.10
Bronze casting was undoubtedly practised, but the art does not appear to have made any great advance at Harappa. It may be inferred that the addition of lead to bronze for casting purposes has evidently not been realised, since none of the bronze objects contains any appreciable proportion of lead.
v1.c12.s6.11
Soldering was well-known to the Indus people and it is very likely that a simple tin solder of its alloy with lead was employed for this purpose. Thus there
v1.c12.s6.12
Table 4.1
v1.c12.s6.13
Chemical Analyses of Copper and its Alloys found at Harappa
v1.c12.s6.14
| S. No. | Description of specimen | Copper | Tin | Antimony | Arsenic | Lead | Nickel | Iron | Zinc | Total | Remarks |
| 1. | Spearhead No. J125 | 97.66 | 0.33 | .. | 0.06 | 0.70 | 0.14 | 1.11 | .. | 100.00 | C.O. |
| 2. | Saw Lot No. 277g/2 | 98.12 | 0.33 | .. | 0.65 | 0.10 | 0.39 | 0.41 | .. | 100.00 | U.M. |
| 3. | Fragment Lot No. 277 | 98.60 | 0.07 | .. | 0.66 | tr. | 0.26 | 0.41 | .. | 100.00 | U.M. |
| 4. | Lance-head Lot N. 277e/2 | 98.69 | 0.10 | .. | 0.68 | tr. | 0.40 | 0.13 | .. | 100.00 | U.M. |
| 5. | Folded sheet Lot No. 277 | 97.69 | 0.15 | tr. | 1.19 | 0.85 | 0.05 | 0.07 | .. | 100.00 | U.M. |
| 6. | Celt Lot No. 277a/19 | 98.37 | 0.00 | .. | 1.40 | 0.11 | 0.10 | 0.02 | .. | 100.00 | U.M. |
| 7. | Needle No. 11859 | 92.55 | 0.29 | .. | 2.96 | 3.72 | 0.21 | 0.20 | 0.07 | 100.00 | U.M. |
| 8. | Dagger | 90.05 | 0.00 | .. | 6.58 | 2.80 | 0.18 | 0.39 | .. | 100.00 | U.M. |
| 9. | Rectangular Rod No. 5133 | 97.20 | 0.84 | 0.19 | 0.70 | 0.00 | 0.09 | 0.98 | .. | 100.00 | C.O. |
| 10. | Chisel Lot No. 277k/3 | 94.92 | 3.60 | .. | 0.60 | 0.20 | 0.29 | 0.39 | .. | 100.00 | U.M. |
| 11. | Chisel No. B 1754 | 92.61 | 6.43 | 0.31 | 0.36 | tr. | 0.20 | 0.09 | .. | 100.00 | P.O. |
| 12. | Dagger No. 4255 | 91.87 | 6.42 | .. | 0.26 | 0.98 | .. | 0.47 | .. | 100.00 | C.O. |
| 13. | Dagger No. 1208 | 91.00 | 6.76 | 0.44 | 0.04 | 0.88 | 0.14 | 0.74 | .. | 100.00 | C.O. |
| 14. | Celt Lot No. 277a/21 | 91.10 | 7.85 | tr. | 0.42 | tr. | 0.22 | 0.41 | .. | 100.00 | U.M. |
| 15. | Awl No. Af150 | 88.38 | 9.16 | 0.42 | 0.40 | 0.10 | 0.17 | 1.37 | .. | 100.00 | C.O. |
| 16. | Chisel X | 87.42 | 10.45 | .. | 1.10 | 0.52 | 0.17 | 0.34 | .. | 100.00 | U.M. |
v1.c12.s6.15
(Note — U.M. = Unaltered Metal. C. O. = Completely oxidized. P. O. = Partly oxidized. Sulphur is frequently present in minute quantities.)
v1.c12.s6.16
is good evidence of soldering of both gold and silver.
v1.c12.s6.17
Another interesting fact is that as in Mohenjo-Daro, löllingite has been traced from Harappa also in the form of a small lump. Its presence is interesting as arsenic may have been extracted from it and used for hardening the cutting edges of tools instead of the tin alloy. (MSV, 99, 181, 367, 378, 384)