This study provides the data of the concentration of released elements for the dissolution, in a glycine solution, of Mg-rich amorphous alkaline earth silicate (AES) fibres heat-treated at the temperature of 700 deg C. It is shown that the heat treatment at 700 deg C facilitates the glass network dissolution of the fibres; the heat treatment also facilitates significantly the alkaline earth elements leaching in the fibres; the (Mg+Ca+Sr)/Si molar ratio of the released elements for the dissolution, in he glycine solution, of the fibres heat treated at 700 deg C is within the molar ratio range for the dissolution of diopside in a buffer solution. This suggests that Mg-rich AES fibres are phase separated and form diopside-like glassy phase as the chemically less durable phase resulting from the heat treatment around 700 deg C.
