This Tuning Fork is made in Aluminium metal and anodized with GOLD coating. These Sacred Solfeggio Tuning Forks are in complete set of 9 tuning forks which include the 3 missing notes in the sacred frequencies known as the Secret Solfeggio. All our Tuning Forks are made from special grade Aluminium alloy and frequency is guaranteed to tuned to an accuracy of +/- 0.25% which is very good for healing.