This thesis intends to extend and improve the database on seismic properties available on mantle rocks.Further, the relevance of different olivine CPO types is discussed and the influence of hydrous phaseson the seismic properties is investigated. Ten samples of fresh, unalterated peridotites and pyroxenites from a suite of 49 samples from the Western Gneiss Region in Norway and from the Bragana massif in Portugal were selected for investigation.