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The Case of the Miracle Oil

Investigative Files

Joe Nickell

Skeptical Inquirer Volume 35.3, May/June 2011

cohost of Miracle DetectivesFigure 1. The cohost of Miracle Detectives examines effigies with trickles of “miraculously” appearing oil at a home in Northern California.

For a new television series on the Oprah Winfrey Network (OWN) called Miracle Detectives, I was invited to a home in Northern California where myriad icons, statues, and other religious effigies were “miraculously streaming oil”—“healing” oil, some claim. There I joined cohosts Randall Sullivan (whose book The Miracle Detective [2004] prompted the series) and Indre Vískontas (a neuroscientist and skeptic) (figure 1). Indre introduced me on the show by announcing: “Joe Nickell is one of the most prominent debunkers of purported miraculous or supernatural events in the country—maybe even the world.” As it happened, I had long ago suggested the case was one of pious fraud (Fernandez 2001). What would an on-site investigation reveal?


The home I visited in Union City, California, belonged to a diminutive Philippine-American woman named Cora Lorenzo. There, in 1991, she hung by the front door in her living room a holy-water font she had bought on a trip to Lourdes, the French healing shrine. One November evening in 1995, Lorenzo noticed that the water had dried up. The next morning, however, which happened to be the Catholic feast of the Pentecost, the font had mysteriously been refilled with scented oil. Both her husband and twenty-four-year-old son denied that they had placed it there.

Soon, word of the “miracle” spread, and visitors—mostly the Catholic faithful—began to come in swarms. Some left their own icons and holy figurines overnight, only to retrieve them the next day drizzled with oil. Claims of healings—from headaches to rashes to arthritis—began to be reported. More visitors came from as far away as Indonesia, Australia, Holland, and Nigeria.

In 2001, the San Jose Mercury News featured the oil story but included more than a trickle of skepticism. A spokesperson for the Diocese of San Jose urged such claims be given “great caution.” Described as “a professional debunker,” I was quoted in observing that nondrying oils like olive oil could remain fresh-looking for long periods of time. (Since they do not evaporate like water, such oils have become favored for weeping-icon trickery.) I mentioned other cases of “miraculous” oily or bloody effigies that ranged from those that remain unproven and those that have been determined to be fraudulent. Moreover, although there were unverified claims of the oil samples miraculously increasing in quantity (rather like the self-replenishing jar of oil in the Old Testament [2 Kings 4: 1–7]), the Mercury News reported that this did not happen to the vial of oil the newspaper received from Cora Lorenzo (Fernandez 2001).

the author and Cora LorenzoFigure 2. The author poses with Cora Lorenzo, whose home is famous as a shrine that pilgrims visit for “healing” oil.

Investigating on Site

When I met Lorenzo at her home on May 24, 2010, she hugged me and said she had wanted to meet me ever since I appeared on a Discovery Channel special on miracles some ten years before (figure 2). The home was filled with effigies, including statues of the Virgin and the children of Fatima, multiple copies of the image of Guadalupe and the Shroud of Turin, and other such reproductions.

Initially puzzled by the proliferation of oil, Vískontas nodded understandingly as we toured the display and I pointed out, using a magnifier, how the oil was often suspiciously placed (figure 3): it was spattered onto a mirror, placed above or outside the eyes of statuary for an unconvincing “weeping” look, separately placed (not dripped from the eyes) onto hands, and indeed was indistinguishable from careless human placement. In addition, Vískontas wondered aloud why the oil would appear not only on religious items but also on walls, door jambs, and the like.

oil-weeping Madonna statueFigure 3. The author examines an oil-weeping Madonna on the porch of the Lorenzo home. (Photos by Joe Nickell)

The Miracle Detectives segment on the case, “Mysterious Oils” (the second part of the January 5, 2011, episode), featured a forensic construction expert, Robert G. Cox, who has fifty years’ experience in building inspection. Cox’s findings matched my own. Demolishing the idea that the oil was somehow seeping into the room from outside—as by Lorenzo possibly having “leaky oil tanks in her attic” (Fernandez 2001)—Cox pointed out that the gypsum drywall was covered with enamel paint, which he observed “is a fairly dense material.” Using a pocket microscope he observed “dots” of oil, indicating it had been splattered onto the wall—similar to the spatter patterns I had noted here and there. Cox concluded the oil was therefore appearing from inside the room.

But was the oil freshly flowing as some people believed? It was never doing so, apparently, when the scene was properly observed. As the Mercury News reported nearly a decade earlier (Fernandez 2001), “During a reporter’s two visits to Lorenzo’s house, oil was present on the walls and statues, but did not flow on either occasion.” I showed Vískontas how a trickle that is already on a statue or icon could go unnoticed from one low-light vantage point, then, as the viewer moved, catch light and glint as if it had suddenly appeared. (I have been at sites where flickering candles placed before an oil icon could cause the trickles to seem to be moving—flowing—
although they were actually static.) There were no unambiguous fresh flows during the two days I was on site.

Still, we agreed to test the issue using video surveillance, although Sullivan was somewhat uneasy, feeling it amounted to “testing God.” However, he said to me, “That’s what you’re here to do is test God, so, yeah.” Lorenzo gave her permission to do whatever we wanted, so we wiped down a large oil-exhibiting statue of the Virgin, emptied the Lourdes font, and then trained a surveillance camera on each. We also placed a small statue in a plastic bag, which Vískontas and I heat-sealed to prevent tampering, and (although not shown on the program) I took custody of another that I monitored overnight in my hotel room. The next day the three of us reconvened at the Lorenzo home to check the results of our tests. Not a single trace of fresh oil had appeared anywhere, as far as we could tell—certainly not on the effigies and font we had under observation. Things were not looking very miraculous.

Healing Oil?

Nevertheless, how do we explain the reported healings? First of all, they are just that: reported. Besides, claims of “miraculous” healing are invariably predicated on being medically inexplicable, so claimants are simply engaging in a logical fallacy, argumentum ad ignorantiam (an “argument from ignorance”)—that is, drawing a conclusion based on a lack of knowledge.

In fact, there are many potential explanations. For example, some illnesses such as multiple sclerosis are known to exhibit spontaneous remission. Other reputed cures may be attributable to such factors as misdiagnosis, prior medical treatment, psychosomatic conditions, the body’s own natural healing mechanisms, and other factors. For such reasons, the international panel of physicians appointed by the Catholic Church to identify “miracles” at Lourdes, the French “healing” shrine, announced in 2008 that it would end the practice. Now the panel will only indicate that some cases are “remarkable.” And remarkable healings may happen to anyone—independent of supposedly magical oil (Nickell 2008).

Miracle Detectives examined the claim of a woman named Marlene Alberto who reported having been miraculously healed of an eye ailment. Her “symptoms suggested” that she had a macular hole in her left eye. Reportedly, doctors recommended she have surgery; she preferred not to accept the risk, instead anointing her eye with oil from the Lorenzo home, whereupon the hole surprisingly closed. The show consulted Ronald P. Gallemore, MD, PhD, who pointed out that “spontaneous closure” sometimes occurs in such cases, with the opening filling in with scar tissue as a result of the body’s own healing processes. Although such spontaneous closures are rare, they are not medically inexplicable and do not warrant the term miracle.

A Case of Deception

When we emptied the Lourdes font using a syringe, we filled some flint-glass vials with the oil—one of which I kept while two others were sent to Flora Research Laboratories for testing. Meanwhile, the show consulted David Stewart, author of Healing Oils of the Bible (2002)—which is published by an aromatherapy company and touts the inclusion of God and his creations (e.g., oil-producing plants) in health care. Stewart sniffed a sample of the Lorenzo oil and found it to have a “spiritual” quality. However, he did suggest that analysis of the oil could be significant since “God’s oils are not synthetic by definition.”

Often, the testing of substances from weeping icons is of little benefit because, presumably, a deity could use any substance it wished and, anyway, it is the question of how the substance got on the effigy in the first place that matters. For example, actual “salty tears” were reported to flow from a plaster bas-relief in Pavia, Italy, but then the owner was secretly observed applying the liquid with a water pistol (Nickell 1997). Nevertheless, in several cases tests have been revelatory. In 1913, a color print that “bled” was exposed when the substance failed tests for human blood; in 1985 a bleeding statue of the Virgin at a home in Quebec was exposed as a hoax when the blood was tested and found to be mixed with animal fat (so that when the room warmed from pilgrims’ body heat the substance would liquefy and flow realistically); and a case in Sardinia in 1995 was solved when DNA tests showed the blood was that of the statue’s owner. In yet another instance, involving a home with statues on which oil appeared in the presence of a comatose girl, the substance proved to be 80 percent vegetable oil and 20 percent chicken fat, consistent with the use of kitchen drippings (Nickell 1999).

With such cases in mind, I was happy the Lorenzo oil was to be tested. The laboratory report was instructive. While the substance was a vegetable oil, tests also revealed the presence of a glycol ether—a synthetic compound used as a fixative by the perfume industry (“in order,” Vískontas explained, “to keep elements together”). Sullivan agreed with Stewart that it was unlikely God would need to use a synthetic material.

With regard to the other evidence (especially the placement of the oil), he said to Vískontas that although he was disappointed, “You and I both agree, I think, that somebody’s putting that oil there.” That had always seemed likely to me, but now there was a preponderance of scientific evidence to that effect thanks to the Miracle Detectives investigation.


Fernandez, Lisa. 2001. Pilgrimage: Many doubt mysterious oil can heal pain. San Jose Mercury News (February 3).

Nickell, Joe. 1997. Those tearful icons. Free Inquiry 17(2) (Spring): 5, 7, 61.

———. 1999. Miracles or deception? The pathetic case of Audrey Santo. SKEPTICAL INQUIRER 23(5) (September/October): 16–18.

———. 2008. Lourdes medical bureau rebels (author’s blog). Available online at; accessed April 12, 2010.

Sullivan, Randall. 2004. The Miracle Detective: An Investigation of Holy Visions. New York: Atlantic Monthly Press.

Joe Nickell

Joe Nickell's photo

Joe Nickell, Ph.D., is Senior Research Fellow of the Committee for Skeptical Inquiry (CSI) and "Investigative Files" Columnist for Skeptical Inquirer. A former stage magician, private investigator, and teacher, he is author of numerous books, including Inquest on the Shroud of Turin (1998), Pen, Ink and Evidence (2003), Unsolved History (2005) and Adventures in Paranormal Investigation (2007). He has appeared in many television documentaries and has been profiled in The New Yorker and on NBC's Today Show. His personal website is at