It's quite rare. I myself wear the Brown Scapular. But
anyway,
http://www.daughtersofcharity-emmitsburg.org/what_new022.htm
WHAT 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]
