It's quite rare. I myself wear the Brown Scapular. But anyway,
http://www.daughtersofcharity-emmitsburg.org/what_new022.htmWHAT IS THE GREEN SCAPULAR?
In 1830, our Blessed Mother appeared to Sister Justine Bisqueyburu, a Daughter of Charity, during her time of prayer. Mary held in her right hand her heart surrounded by flames, and in the other hand a kind of scapular. It was a single piece of green cloth rectangular in shape and hanging by a string which was green. On one side was a picture of the Blessed Virgin and on the other side was "a heart all ablaze with rays more dazzling than the sun, and as transparent as crystal." That heart, pierced with a sword, was encircled by an inscription of oval shape surmounted by a gold cross, and thus worded: "Immaculate Heart of Mary, pray for us now and at the hour of our death."
THE GIFT OF THE GREEN SCAPULAR
An interior voice revealed to Sr. Justine the meaning of the vision. She understood that this new scapular and the prayers of those who used it would be a means that God would use to bring to Himself those who had no faith and to reconcile those who had strayed from their faith. Thus would they be assured of as happy death. The scapular was distributed, and God granted wonderful conversions and healings, both spiritual and physical.
In wearing the Green Scapular, we honor the heart of Mary. We remember that her heart is a symbol of her love and her response to God. The scapular can be worn around the neck, on the clothing, or placed in the room of the one for whom the prayers are intended. The prayer surrounding the heart should be repeated daily, if not by the one wearing it, then by the one giving it.
You are invited to make use of this gift of Mary to grow closer to her Son, and to ask her, through the Green Scapular, to pray for you and for those whom you love.[/url]
