I understand your argument, but actually there is the part of the transformation of the transparent crystalline Silicon send a link talking about this process facially, but I don't find the process exactly as it is manufactured as an image explaining step by step, as an example process lithograph for example.Silicon is transparent at longer wavelengths and absorbs
at shorter optical wavelengths. There is no "transparent
silicon" in the sense that glass or sapphire, is transparent
to wide ranges of wavelength.