Optical Spectra of Rutile, TiO₂ 

• Watson TL (1912) Vanadium and Chromium in Rutile and the Possible Effect of Vanadium on Color. Journal of the Washingotn Academ of Sciences II, 431-434.
• Khomenko VM, Langer K, Fett A (1996) Electronic absorption by Ti³⁺ ions and Ti³⁺ Ti⁴⁺ charge transfer in synthetic blue rutile. Mineralogicheskii Zhurnal 18, 12-17.
• Khomenko VM, Langer K, Rager H, Fett A (1998) Electronic absorption by Ti³⁺ ions and electron delocalization in synthetic blue rutile. Physics and Chemistry of Minerals 25, 338-346.
• Bromiley GD, Shiryaev AA (2006) Neutron irradiation and post-irradiation annealing of rutile (TiO_2-x):effect on hydrogen incorporation and optical absorption. Physics and Chemistry of Minerals 33, 426-434. 
• Emeline AV, Sheremetyeva NV, Khomchenko NV, Ryabchuk VK, Serpoine N (2007) Photoinduced Formation of Defects and Nitrogen Stabilization of Color Centers in N-Doped Titanium Dioxide. Journal of Physics Chem C, 111, 11456-11462. 
• Choudhury B, Choudhury A (2012) Dopant induced changes in structural and optical properties of Cr³⁺ doped TiO₂ nanoparticles. Materials Chemistry and Physics 132, 1112– 1118
• Palke A (2023) Exceptionally Large Synthetic Rutile. Gems & Gemology 59, 81-82.