Marian apparition

A Marian apparition is an alleged phenomenon in which visions or images of Mary (the mother of Jesus) are perceived to appear in modern times. It usually takes the form of a situation where a Christian might see an image of Mary, while a non-Christian sees in the same image either nothing or a generic woman's image- for instance, the heroine of a romantic novel. Many Christians (especially pastors and those on Crazy People Central Facebook) love to use these images as an example to "prove" that Mary actually walked the Earth and therefore the rest of the Bible is true and their particular god is real (One has to wonder why nobody points to it as "evidence" that the heroine of a particular romantic novel is supposedly a 100% real woman.)

These can be visions claimed by one person, appearances alleged to have been seen by large numbers of people in a particular place, rumors that an image of Mary is appearing on a particular rock formation or shadow at a certain time of day, etc. Some of these perceived "sightings" of Mary are forms of religious pareidolia, in which "Mary" is seen in an ordinary object. It can be very easy to perceive images in random everyday objects that appear to confirm beliefs you already hold, especially if said beliefs are not supported by any evidence and you really, really want them to be true.

Examples
Some of the most famous "Marian apparitions" allegedly took place in Lourdes, France and Fatima, Portugal- both with their own respective miracle claims.

In the United States, the visions of Mary by Veronica Lueken from 1970 to her death in 1995 in Bayside, New York were heavily promoted with billboards and a 1-800 number you could call for a packet of brochures on Mary's message. Mary's message as channeled through Veronica Lueken was heavily infused with apocalyptic warnings of a coming New World Order conspiracy, because of fucking course it was.

In 2004, a woman put up for sale a 10-year old grilled cheese sandwich, which she said had an image of the Virgin Mary on it. It fetched $28,000.00 on eBay despite having a bite taken out of it. Eternal salivation salvation may be tempting, but come on, you just can't get enough melted cheese.