Seemingly, the diffusion coefficient is sensitive to impurities or structural issues from the crystal, but that remains for being quantified. For our tough estimates of time at temperature needed to take out the hydrogen from our samples, the hydrogen diffusion coefficient picked is that given by Belonoshko et al. (2004), https://www.tumblr.com/thegemjournal/759696203354128384/understanding-the-unique-characteristics-of-yellow?source=share