In the quest for new blue chromophores with less usage of cobalt alternatives to the carcinogenic and expensive zinccobalt aluminate system, we developed cobalt doped phenacite type zinc germanate system. Rietveld analysis reveals that the CoO 4 tetrahedron intensely experienced Jahn-Teller distortions leading to irregular geometry on substitution. The UVvis-IR absorption spectra exhibit intense Co 2 + d-d transitions with three fold splitting associated with the CoO 4 tetrahedron in the visible and IR region, indicating low symmetry. The crystal field strength 10Dq, Racah parameter and Nephelauxetic ratio variations reflect on the improved covalency of the Co 2 + environment. Thus the synergetic effect of Jahn-Teller distortions and covalency of the CoO 4 tetrahedron lead to strong absorptions in the green to red region resulting in intense blue colors with low cobalt content (2.2 to 8.9 mol %). The typical composition Zn 1.6 Co 0.4 GeO 4 exhibits intense blue hue b * = À 58.64, much higher than that of the commercial CoAl 2 O 4 system.