Lithium iodate (LiIO3) is a negative uniaxial crystal[1] for nonlinear, acousto-optical and piezoelectric applications.
It has been utilized for 347 nm ruby lasers.
[9][10] Mohs hardness of lithium iodate is 3.5–4.
Its linear thermal expansion coefficient at 298 K (25 °C; 77 °F) is 2.8·10−5/°C (a-axis) and 4.8·10−5/°C (c-axis).
[1] Its transition to β-form begin at 50 °C (122 °F) and it is irreversible.