Gems, from my faulty memory. Faulty, because directions may be 'slightly' off.
1. on wooden beam in small hallway leading towards the library, with staircase to Thaddeus rooms in the west
2. Library, on top of bookshelf
3. On old (inaccessible) balcony, right in front of the scriptorium to the east
4. Main chapel, on pillar with statues
5. A room/side-chapel in the north with 4 huge statues (like 6 meters high) standing back to back to each other and a novice buzzing around them. On top of those statues. Not sure if this is a ctually considered a gem, as it looks like a spice bag.