Blood pebbles

From LSWiki

   This is several black hematite pebbles.  This is a set of blood pebbles, a form
   of symbiotic armour.  Numerous small pebbles are embedded in the owner's flesh,
   enchanted so as to draw power from the magick in hir blood and channel this energy
   for defense.  Implanting the pebbles is a simple, if excruciating, process. 
   Removing them once implanted requires exotic procedures.  It is permeated by a dim
   shimmering radiance.  You estimate its value at about one thousand five hundred
   gold.  
   It is in perfect condition.  
   It is intermediate in size, and looks just about right to fit you.  It looks
   about twenty-one dimins tall, about six and three tenths dimins wide, about two and
   a tenth dimins long, and less than a twentieth of a dimin thick.

Notes

This works as epidermal armor, implanted under the skin of the user. If the user loses a limb, there may be consequences as the rest of the array is forcibly de-implanted.

While implanted, this provides some armor, a +200 bonus to Metal Affinity and an undetermined bonus to Cutting Resistance. (may be crushing resistance, did not have knowledge of either resistance skill to verify)

Spoilers

If you'd like to acquire a set of your own, there is a forgotten ruin on another plane that might be worth a closer look.