Notes: An interesting cultural term - despite some phonetic problems, undoubtedly common NC. Cf. also Hurr. ošχo(-ne) / ušχu(-ne) 'silver' (see Diakonoff-Starostin 1986, 46-47), where -šχ- regularly goes back to the cluster *-rc-. The early PHU form *Hwercχ- (reflecting an intermediate stage in the process *-rc- > *-rcχ- > *-cχ-) was borrowed in Proto-Kartvelian as *werc̥1̇χl- (the comparison of PK, PWC and PEC forms was first suggested in Charaya 1912, 11). A similar form exists also in Semitic (Proto-Semitic *ḥrṣ); it is therefore impossible to suggest a simple loan from Indo-European *rǵnto- in Caucasian languages - to say nothing of enormous phonetic problems arising with this supposition. Although some Caucasian forms may have experienced Indo-European (Indo-Iranian) influence (see above in the WC section), it seems rather more probable that PIE had borrowed this archaic Near Eastern root, which on Indo-European ground had contaminated with the pure Indo-European root *Har(ǝ)ǵ- 'light, white'. The root reveals a "floating" labialisation: some forms are best explained by a protoform *ɦĕrVcwĭ (PL, with spirantization of *-c-, PWC), some - by *ɦwĕrVcĭ (Av.-And., PD, HU). It is interesting to note the Ossetian name of 'silver': ävzīst / ävzestä (having penetrated into Fenno-Ugric: Udm. azveś, Komi ezyś, Hung. ezüst, see Abayev 1958, 213). The Indo-European etymology of this word (see ibid.), belonging to Petersson, is very dubious, and it can also have a NC source (reflecting the original labialisation).
Finally it is interesting to note the similarity of this root and PNC *rĕwcwĭ 'gold, red copper' (q.v.): perhaps it is possible to think of an archaic word-derivation with a laryngeal prefix.