If you hit someone with a Bedrock Sword, the Bedrock Chestplate of the attacked will disappear. I think this is a bug, because Bedrock should be unbreakable, even with a bedrock sword. I also noticed that the Chestplate is the only part of the armor that has no "number" on that hud on the left bottom.
The bedrock chest plate should not actually disappear. It may disappear to you when you hit them, but it should still be in their inventory, or reappear after a few seconds. I have hit mobs and it removed their armor and then it comes back after a bit. It plays the breaking sound, but in reality it is just unequiping that item, or at least it should be. The number thing is of no concern at all. Most likely an issue with the HUD and not the armor. If the armor is actually not placed in the player's inventory, or it does not come back after a few seconds, then this needs to be reported here: http://www.minecraftforum.net/topic...kas-mods-tech-worldgen-civilization-and-more/
This happened to me also and I did not get it back as you state Nolan. So maybe this is an issue that we need to address. Hakalaken hit me by accident and we couldn't work out what actually broke it but it was his bedrock sword.
I can confirm this has happened to me and my friend several times, and the chestplate does indeed break. It may or may not be related to the bedrock sword which happens to break armor incredibly fast. (We've tested with a bedrock sword on iron armor and it took half damage then broke in 2 hits from a bedrock sword.)
Bedrock sword is designed to destroy armor, although I don't think it is supposed to destroy the bedrock armor.
