Wow?! and the difference between something made of energy, or a hologram as such is a real mind boggle, since when does an argument come into something that can only be defined as a masterpiece?? *NEEERRDDD RAGE
From the Mass Effect Codex, "The most common melee design is the "omni-blade," a disposable silicon-carbide weapon flash-forged by the tool's mini-fabricator. The transparent, nearly diamond-hard blade is created and suspended in a mass effect field safely away from the user's skin. Warning lights illuminate the field so the searing-hot blade only burns what it is intended to: the opponent."