The main objective of this practical session is to introduce the student in the study of physical properties of minerals and specifically optical and mechanical properties. This is one of the most interesting fields in Mineralogy and we can use these properties to obtain the mineral identification. Activities that we propose have the study of gem-minerals as a basic objective that is the minerals that according to special characteristics and after cutting by man we use as a precious stones or gems. All techniques that we use are not destructives that is without any modification in the specimen, a very important question when we use minerals as gemstones. The practical session are distributed in six working groups with a reduced number of students (2-3), using this system we can combine the necessary equipment in the best possible way. Main objectives of the practical session are: showing one of the practical uses of minerals and the use of special techniques for to obtain the identification of gem-minerals. Also is very important to compare the theoretical concepts with the practical applications
