Go have a look at the new publication on American Mineralogist by Kira Musiyachenko where she demonstrates with ab-initio calculations that pure rutile inclusions in metamorphic garnets do not develop positive residual pressures upon exhumation. In the manuscript Kira also reveals the secret of the birefringence halo around some rutiles in garnet from Pohorje eclogites. These rutiles have a hidden neighbor: tiny amphiboles at the host-inclusion boundaries influence their elastic properties! To explain this mathematically, we developed a model describing the behavior of such mixed-phased inclusions.