User blog comment:Songflower/Essay: Could the Redwall Books have really happened?/@comment-1209332-20090801230339

Comets are made of ice and rock. Even worse for sword making. The closest thing to indestructible metal would probably be Titanium (which is, by the way, called the "space age metal", and the easiest way to produce it is to use a high explosive to heat pure elements to 700-800 degrees Celsius) and that wasn't even discovered, much less used until the 1791.