[The following is taken verbatim from Christina Gallagher's official website.]
In an early apparition in March 1988, Christina received a request from Our Blessed Lady, that a special medal be struck; “I would like My Son’s Cross on it, with me on My knees praying for My children. On the other side, I would like the two hearts (of Jesus & Mary) weeping tears of blood.”
When asked by the visionary what the medal should be called, Our Lady replied:
“Simply call it The Matrix. My Son wishes to mould.”
Christina was asked by her spiritual director (Rev Dr Gerarad McGinnity) to make sure that she had the name correct, as he thought it might be ‘Mediatrix’, but the visionary was correct, as Our Lady confirmed the name of the medal when Christina next saw her in appartition.
On the same occasion, Our Lady stated:
“My child, My Son and I hurt very much when our children do not hear us. Their hearts are closed to us. Pray, pray, pray and make sacrifices to My Son’s Heart, that people will hear us calling them.”
Mrs Gallagher did as She requested and The Matrix Medal, as it is called, has been available for some time.
Many Matrix Medals have already been produced and distributed all over the world and there are numerous reports of spiritual conversions and healing, also of physical healing and cures recorded.
Beautiful testimonies have been received of individual as well as family conversions by means of the Matrix Medal. People outside the Catholic Church have been brought to seek the true faith and people within the Church who had lapsed from the sacraments have been brought back after as long as thirty years absence.
When asked about the Matrix Medal, Christina said that she has heard of many conversions and also cures through the medal, but those graces were from God and while Our Lady had asked for the medal through her, what people received had nothing to do with her. She only learned of these things from other people and she does not distribute the medals. She had heard of a young man who was in danger of death after being struck by a hurley ball, and of a child with cancer, and various other cases and of instance where people were away for a long time from the Church and the Sacraments, and who received graces and returned, through the use of the medal.
[...]
http://www.christinagallagher.org/en/xmatrix.htm
[Go to her official website to learn how to get the Matrix Medal!]