Ultrasonic cleaners tend to remove the oxidized finish so the best way to care for your jewelry is to clean it with soap and water. Store it in a clean dry place.
Do not use a traditional polishing cloth on your matte finished jewelry as this will restore a shiny finish. You can use a fine steel wool pad to clean your pieces, and since they are textured, you won’t ruin or scratch the finish.
For the oxidized pieces, over time the patina may wear, so I am happy to re-oxidize the piece. Please reach out to me at firstname.lastname@example.org.