Crafting Vajra with Fragment Crystal or Transparent Crystal only has a 3% success rate, so if it fails then you'll get nothing. Crafting it with Essence Crystal is 30% success rate, Unknown Tinder (x15), Chromatic Tinder (x5) and Ancient Tinder (x5) have 100% success rate.
Stone of the Brute giving 15 vit is a description mistake, will be fixed