Indeed, in the past, some traces between Etruscans and Sardonic prehistoric tribe cultures have been made, with regards to language, nuraghi and metallurgy. Even in modern Sardonic, some linguistic traces seem to lead to Etruscan, but after careful research, the evidences have been considered as too poor to state a realistic link between the Etruscan and Sardonic languages. Nuraghi were used for various purposes, one of which seems to have been the use of sifting pure iron, copper et al. out of metal ore. There have been other usages for the nuraghi, but these are quite vague and the scientific opinions on these usages vary from time to time and from archaeological school to archaeological school. In the Etruscan area, metal ovens have been found. The oldest ones and the ones in the archaic periods were relatively small buildings, set away semi-subterraneously. This seems to relate a bit to nuraghi as well, but nuraghi varied more in size than the Etruscan ovens found until now.
It's quite bold to say that the Etruscans descended from the Sardinians. Maybe there is some relationship, and if these Sardonic people came to the Northern-Italic coasts around 1100-1000 B.C., they might have come from elsewhere (the "big elsewhere", where the forebears of the Etruscans came from: Asia Minor somewhere? That discussion still goes on as well!) and split their route: some of them went towards the Sardonic coasts, others went to the Northern-Italic coasts. Maybe these people had a common knowledge of metallurgy and a language which settled down in Northern-Italy in some way (mixing up with indigenous languages there) and which settled down in Sardinia in another way (likewise). Sardonic people comeing to Etruria around 1100-1000 B.C.....Possible; but I tend to think, that it kind of happened like I traced out just above.
Evidence of all of this, however, is still quite poor and much remains the object of speculation. There is a good chance that Sardonians and Etruscans were related peoples some way or another, the question is only: when and how exactly?

Tanaquil