Can there be a sword made of real diamond?

The largest raw diamond ever found fit into the palm of a grown man's hand. (The Cullinan diamond, gifted to the British Monarchy in the early 1900s.) What this means is that you probably won't be able to find a raw stone large enough from which to craft a sWord.

However, even though the practical creation of a diamond-bladed sWord is not currently possible, it is possible to shape diamonds in such a way as to cut other objects. In fact, most diamonds, rubies, sapphires, and other hard precious and semiprecious stones are cut using diamonds. If we ever discover an effective way to create artificial diamonds, diamond sWords could become a possibility.