Hi,I'm sorry to be back with all my questions after almost 2 months,but inspite of all my books and websites, I can't find any complete description of phase diagrams of solid solutions and of peritectic mixtures. I have my exams next week,so please try and help me within that period....as soon as my exams begin I'll be completely tied up with my other subjects also. Here are all the doubts I have in regard to solid solution phase diagrams....I have only one more set of questions for peritectic systems..... (In reference to http://csmres.jmu.edu/geollab/Fichte.../SolidSol.html [Broken] ) We consider the phase diagram of Anorthrite and Albite solid solution...I'll refer to albite as Na and anorthrite to Ca, as these are the major metals involved (They've done the same thing on the website also).. 1. Why does calcium freeze so drastically at the beginning (of the freezing process of the liquid melt)? 2. While initially the rate of crystallization of calcium is greater, why does sodium incorporation (into the forming crystal) start increasing as the crystallisation continues? 3.Why will the first crystal formed due to solidification of calcium consist of any sodium at all -sodium has a much lower freezing point? 4.Is the liquidus curve in the albite-anorthrite curve in any way similar to that of the simple two component eutectic mixture (Like lead and tin)? 5. Why are there two curves-solidus and liquidus--(in the diagrams for the simple eutectic systems,the liquid phase and forming cryatal phase were represented on the same diagram)? 6.What does it mean to move down a vertical line crossing the liquidus line, solid + liquid region and the solidus line?