Rigvedic soma as a metallurgical allegory: soma, electrum is deified
A significant attribute of ams’u is s’ukram as noted by Rishi Atri Bhauma, devataa vis’veda:
das’a kshipo yunjate baahoo adrim somasya yaa s’amitaaraa suhastaa
madhvor sugabhastir girishthaam canis’cadad duduhe s’ukram ams’uh
RV 5.043.04 The ten express of the juice, (the fingers), and the two arms of the priests, which are the dexterous immolators of the Soma, take hold of the stone; the exulting, skilful-fingered (priest) milks the mountain-born juice of the sweet Soma, and that Soma (yields its) pure juice. [The text has only s'ukram am.s'uh = sa ca am.su'h s'ukram nirmalam rasam dugdhe, and that Soma has milked the pure juice; or am.s'u may be an epithet of adhvaryu, the extensively present priest, am.s'ur vya_pto adhvaryuh]. Alternative trans.: The ten fingers, the two arms, harness the pressing stone; they are the preparers of the Soma, with active hands. The one with good hands has milked the mountain-grown sap . . . the amsu has yielded the dazzling.
The lexeme s’ukram is interpreted as ‘pure’. In the alternative translation, s’ukram is interpreted as ‘dazzling’. This latter semantics related to ‘brightness’ is attested in RV 5.045.10 Su_rya has ascended above the glistening water, as soon as he has put to his bright-backed steeds; sage (worshippers) have drawn him, like a ship, across the sea; the waters hearing his commands, have come down. [Su_rya has ascended: su_ryo aruhat s'ukram arn.as = su_rya has mounted the bright water, that is, he has become everywhere visible, but it may be an allusion to the sun's rising apparently out of the sea].
The attribute s’ukram becomes meaningful in the context of a recently-discovered manuscript attributed to Maharshi Bharadwaja (anonymous text is dated to 1931 and attributed to the dictations of the late Pandit Subbaraya Shastri of Anekal – 1855 to 1940 CE), which is said to be titled Ams’u Bodhini as Chapter 1 of Yantra Sarvasva, followed by Vaimaanika S’aastra (quoting Lohatantra), Kritaka Vajra Nirn.aya. The text refers to tamogarbha loha (light-weight alloy), pancha loha (copper alloy, malleable and corrosion resistant to moisture and salt water), arama tamra (alloy of copper, zinc, lead, iron for light absorption). http://www.eswaraindia.org/l-a.htm
In the Babylonian Talmud (+2nd century), asemon is a commonly used word referring to bullion (gold, silver or mixed.) Leiden X papyrus (c. +3rd century) says: “no.8. It will be asem, (i.e. electrum, an alloy of gold and silver)which will deceive even the artisans (a tin-copper-gold-silver alloy); no.12. Falsification of gold (a zinc-copper-lead-gold alloy)...” (cited in Needham, Joseph,SCC, vol.5, Pt. II, pp. 18-21). “The existence of this alloy (assem) may have been the original cause for the suggestion of transmutation since by adding silver to it, one would get a metal nearly identical with the crude silver from the mine; and by adding gold, something indistinguishable from gold. [The paucity of the Egyptian language may perhaps have been responsible for a confusion. Gold was the ‘yellow metal’, and the alloy produced was also a ‘yellow metal’.]” (Hopkins, A.J., Alchemy, 1967, pp. 103-104).Metals were not fully distinguished from their alloys; all carried names such as aes, electrum etc. Ayas meant metal. Asem denoted the natural alloy of silver and gold; it also meant any bright metal made with copper, tin, lead, zinc, arsenic and mercury. Twelve or thirteen different alloys were called asem (Needham, Joseph, Science and Civilization in China, vol. 5, pt. II, p.45). Asem was Soma; this hypothesis will be the running-thread of this review of the alchemical tradition of ancient India, dating back to R.gveda. Hopkins states: “At Gungeria, in district Balaghat, 102 pieces of silver plates were discovered along with 424 copper implements. The silver was found to be admixed with 3.7% gold (...1100 B.C. - 800 B.C.). The presence of 3.7% gold in these silver pieces indicates the extraction of silver from electrum...” (Smith, V., 1905,Indian Antiquary, pp. 233 ff.; loc.cit. Bharadwaj, H.C., Aspects of Ancient Indian Technology, Delhi, Motilal Banarsidass, 1979, p. 138). The parallels with the Indian alchemical tradition are apparent: tan:kam gold in dravidian-Chinese becomes t.an.kan.a borax (a reagent!) in indo-aryan, t.an:ka gold coin; the terms hiran.yam, hema-bìjam, connote the yellow metal. The word, thong, means ‘copper’ in Thai language.
na_kam black lead; zinc; prepared arsenic; sulphur; na_kacam, tu_riyam, vermilion, lead (Tamil.lex.)