It depends in what context. generally if someone sais rune stones, they mean the Norse ones from either Younger Futhark, Elder Futhark or possible Anglo-Saxon Futhark. The most common of these is...
a rune stone is a magic stone that you use in runescape and it is magical when it has been blessed and you can do it to make spells and to kill people lololololol rune stone can also just be a stone...
There is a summoning monster that teleports you close to the altar...i believe it is called a spirit graahk u need 56 summoning i believe...REALLY fast way to make nature runes