The fabric of pottery consists of about 50% or more of silica, mostly chemically combined with the oxides of aluminum, calcium, and magnesium. Apart from these, iron in the form of various oxides is present, as well as a long list of minor and trace constituents. These are all present in the clay from which the pottery was made, but the numerical values of their concentrations will be different for two reason. This booklet lists the average values and ranges of the concentrations for all the groups collected. Statistics are given for the following groups: Mycenae, Bergati, Korakou, Megara Minoa, Knossos, Ayia Triadha, Gournia, Palaikastro, Tylissos, Zakro II, Perati, Thebes I & II, Amarinthos I & II, Volos I & II, Marmariani, Zakra I, Palaikastro, Phylakopi I, II, & III, Ialysos I, II, & III, Arpera Chiflik I & II, Enkomi I & II, Hala Sultan Tekke, Tel el Amarna, Tell Atchana, Ayios Stephanos, Aegira, and Argyropoulis I & II. Some of the provenances are: Korakou, Megara Minoa, Perati, Thebes, Argyropoulis, Gournia, Palaikastro, Phylakopi, Arpera Chiflik, Tell el Amarna, Ayia Triadha, Palaikastro, Zakro, Phylakopi, Ialysos, Tell el Amarna, Mali, Evretadhes, Aloupotrypes, Arpera Chiflik, Ayia Paraskevi, and Verghin.