The only rune I can think of (at the end of Act 3) is the one in the kikimore queen's lair (on a dead body in the collapsible tunnel), which is found in the act-ending quest between Acts 3 and 4.There is a Witcher wiki which lists all runes & meteorite stones and where to get them. Just Google: Witcher Wiki Meteorite.Alternatively, find the Harvall sword in the swamp (wyvern island). It is only surpassed in steel by the 3 red meteorite reforged sword.You should be able to finish Act 3 and get a quest-related silver sword at the end of Act IV. And of course, more rune stones can be found DURING Act 4.Most people don't need to reforge their silver one EVER in the game, as long as you use oils and get Aerodight later.