Palantiri

[Inziladun]

Originally Posted by Rumil

So either they were brought to the Numenoreans out of Tol Eressea, during the times that the elves still had good relations with the Kings, or they had been given to the Three Tribes in Beleriand, or they were a gift from the remaining elves (eg Gil Galad) during the Second Age.

The implication appears to be that the Stones were given to the Faithful of Númenor by the Eldar of Eressëa before the Downfall.

And Seven Stones (the Faithful) had, the gift of the Eldar.

Akallabêth

If the Númenóreans had been in possession of the Stones from the time of the First Age, surely the Faithful alone would not have been allowed by the Kings to solely possess them on the island, and Elendil and Co. would not have been able to take them when they fled.

As for their usage during the First Age, I rather think the Noldor in ME did not have them. It's unlikely they would have avoided capture by Morgoth, and I don't see how seven of them would have been saved from the wreck of Beleriand in the War of Wrath at any rate.