Michael holding the Nephilim Shard
The Nephilim Shard is a 75mm long reflective red metal shard with a distinctive shape, glowing with a subtle white Nephilim Fire.
It has a very short reach, but it is devastating in hand-to-hand combat. Against normal enemies it inflicts massive damage and sets them ablaze with Nephilim Fire. It is the only other weapon in the game, other than the Nephilim Blade and the Malignum, that will finish Grigori.
(from Shadow Man 2econd Coming Game Scriptment)
The Nephilim Shard is given to you by Deacon the first time you see him; immediately after you find Jaunty and the ten bird skulls.