>>14198355The d orbitals of the iron contained within jade are split, probably into two sets, due to the specific environment around the iron ion (crystal field). Between these sets of orbitals there is energy difference that corresponds to the photons of red colour. Hence the red photons get absorbed and mostly converted to heat energy (invisible radiation), the rest of the white light is perceived as green. Same thing in green plants (here it's magnesium ion), they absorb around 680 nm (red) and white light minus red is green and that's what we see.
