Question: where are all the resonance gems in solstheim?
Answer: One sold by Revus Sarvani near Tel Mithryn.
Two carried by a Reaver Lord/Marauder in Kagrumez.
One found in Fahlbtharz. In the final room, on a plate next to the Visage of Mzund.
One found in ​Nchardak Aqueduct. On a table in the upper northeast room.