Dear all, This is a subject that is beating my mind latelly. I am working with UHT granulites from Brazil. It is very commom in these rocks to see rutile inclusions in Grt, rutile and sillimanite needles in Opx clevage, and rutile needles in quartz are abundant too What is the meaning of these oriented needles in Opx and Qtz? As Opx has very high Al2O3 in these rocks (between 6 to 14 %) we could imagine that Sil needles represent exsolution os Al2O3 during the retrograde stage, as well as the Rut needles, what is not easy to prove and probably it is not the case for Rut needles in Qtz. If we have a mechanism that could take in account all these features I would guess that melting of a Ti-biotite producing Sil, Rut, Opx and/or Grt + Melt can be a good explanation. Rut and Sil grew together with Opx but crystalographic oriented in the clivage planes and with random distribution in Grt and Qtz. It is not an entirely original idea of myself, as I have been talking about these with some friends latelly, but I will keep their names as I can share the guilt alone if it is not a good explanation (but I think it is). Renato