- Brass gilded with 18 carat fine gold - Petrol blue and green or red crystal ✔ In order to keep the shine of Shyloh costume jewelry, you can clean them regularly with a small soft brush, water and a little soap, rinse then place them on a clean cloth and wipe them dry with a fine cloth. ✔ Avoid contact with water, chlorine, sea baths, household products, perfume or any cosmetic.