AgGaGe5Se12 is a promising new nonlinear optical crystal for frequency-shifting 1um solid state lasers into the mid-infrared (2-12mum) spectral range. Because of its higher damage threshold, larger birefringence and bandgap, and greater variety of phase-matching schemes, AgGaGe5Se12 could become an alternative to AgGaS2 and AgGaSe2,more widely used in high-power and specifific applications.