Abstract
Tourmaline is known as a gemstone with great variety in color and composition. Some color centers are related to transition metal ions, others to radiation-induced electron–hole traps. The knowledge concerning the microscopic structure of the color centers is very poor. Therefore, color enhancing processes by irradiation and/or thermal treatments in tourmaline are performed empirically. By electron paramagnetic resonance and electron nuclear double resonance a yellow color center produced by γ-irradiation in colorless Li-bearing tourmaline (elbaite) has been identified. The color center is proposed to be a hole trap of type O − showing mainly superhyperfine interaction with two Al nuclei. During the irradiation process atomic hydrogen H 0 is also produced which shows the same thermal stability as the hole trap (250 °C).
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
