Sentirum is a gem acquired through mining in the Plains of Eidolon that can be acquired from blue veines. Additionally, successfully hitting the special narrow brackets during mining will grant additional gem rewards on completion, even on red ore veins.
It can be refined to make Radian Sentirum or traded for Ostron faction standing at Old Man Suumbaat for 
400 each.
The Advanced Nosam Cutter or Sunpoint Plasma Drill is required to mine this gem. This gem has a 15-30% chance to drop from blue mining nodes, depending on the quality of the cut.
It seems to have a a better spawn rate at night.
Notes
- 1x Sentirum is required to achieve Kin with the Ostrons.
