Far-infrared mineral spectra database for the analyse of future PACS/Herschel data

The si-nature of carbonates has been found in both protoplanetary disks of evolved stars and environment of low mass protostars (Kemper et al. 2002, Ceccarelli et al. 2002). Both carbonates and sulphates are present in primitive carbonaceous chondrites. On Earth, the formation of carbonates (CO32-) is usually associated with sulphates (SO42-). Although the formation of such species is obviously different in the interstellar medium than on Earth (where it usually involve liquid water), we propose to search for the feature of sulphates in the environment of protostellar objects using PACS. For that we have started the construction of a far IR database of experimental spectra of minerals including sulphates. This database will be a useful tool to study the mineral composition of interstellar dust. In this contribution we will present the preliminary results of these studies.