Adapted from an article by Antonio Schlatter published in "Almudi": De material refractario.
The origin and nature of the "tilma" of Saint Juan Diego with the image of Our Lady of Guadalupe is still a mystery. The fact that scientific studies have only served to reveal some of its miraculous properties shows us that science, when it is truly scientific, strengthens our faith, since it has more need of it. The fabric has been preserved, with its marvelous image, for almost 500 years in a humid and salty environment. It has withstood nitric acid being spilled on it, and the explosion of a nearby bomb. It is a fabric that seems to be "refractory" to the dust, insects and humidity found in most of Mexico. What is it made out of? It is certainly a mystery.
But such mysteries generate questions that inevitably lead us to turn to God. Nevertheless, God is interested not so much in the clothes people wear as in the people who wear them. God came in search of Juan Diego, and made use of his cape to attract that son of his, along with the millions of people drawn to Him over the centuries through the miraculous image of Our Lady of Guadalupe. And if He works miracles with fabrics, how much more care He takes to ensure that people are made of good material. The entire human race, created in the image and likeness of God, has been made with a "guarantee of good quality." But as with fabrics, in some cases (for example, with saints like Juan Diego) God outdoes Himself and forces us to ask the question: what material must that person be made of to reach where he reached, and live as he did?
Last December 12, feast of Our Lady of Guadalupe, was the centenary of another Guadalupe: Guadalupe Ortiz de Landázuri. Looking at her holy life and the testimonies that continue to arrive in her process of canonization, we can ask ourselves: what was Guadalupe made out of? And the surprising thing is that, if we look at the characteristics of that miraculous "tilma," alongside the masterful combination of "clay and grace" of which Guadalupe was made, we see that they coincide in something to which she devoted much of her energy and professional work: refractory material. It was precisely on this topic that she wrote her doctoral thesis and spent many hours investigating. Perhaps, without meaning to, she was revealing here her own "secret."
A passion for chemistry
Guadalupe's professional passion was chemistry. Those who knew her and lived with her say that she always had a chemistry book with her and that she would review it whenever she had a free moment. Her professional plans coincided with her divine vocation to the point of becoming one thing. Also for this reason, right from her first conversation with the founder of Opus Dei, it was so clear to her that she had found the path God wanted for her life.
Guadalupe's life was a constant "yes" to whatever God asked of her. Together with the many different tasks entrusted to her in directing the apostolic work with women, she always preserved her passion for chemistry, first in a general way and then focusing on fields of investigation that interested her more directly.
While director of the Zurbaran residence for women in Madrid, she got in contact with Piedad de la Cierva Vindes, who had a doctorate in chemical sciences, and whom she had known even before going to Mexico. Guadalupe decided to begin, under her guidance, a thesis on "insulating refractory materials," with a specific concern for properties of rice husks. She carried out a detailed study of these materials, despite having to make great efforts to acquire the resources needed for these experiments, and despite the serious heart condition she suffered from and that forced her to interrupt her research quite frequently.
The refractory humanity of Guadalupe
"Refractory materials" are those able to resist very high temperatures, without undergoing internal deterioration. While "refraction" refers to the capacity of certain bodies to make rays of light or other radiation change direction. Both meanings could be applied to Guadalupe.
The following testimony by a person who knew her well shows us the "resistance" that marked Guadalupe's character: "Although she was someone who always wanted to go unnoticed, her virtues truly made her stand out. One feature really drew my attention: her permanent smile. Guadalupe was a person who laughed a lot and always smiled. I think this was a sign of how completely she forgot about herself. She was totally detached from her precarious health situation. Another striking feature was her simplicity. She spoke with great naturalness, saying exactly what was on her mind."
Guadalupe was resistant to all that life threw at her, like refractory materials. "She was very self-sacrificing. Often at night she couldn't sleep, owing to severe respiratory problems, and had the sensation of suffocating. Once she remarked, laughing: Last night I thought I was dying, that my final moments had come. I didn't want to disturb anyone so I just lay there quietly. I told myself: I've gone to confession, and made an act of contrition and abandonment. If I die, what more could I do? She accepted her illness in an extraordinarily serene way."
Like refractory materials, the pressures of life didn't lead to any interior deterioration. Rather her love for God grew ever stronger. For example a note she made not long before dying reveals her deepest desire: To plunge deeper into silence and reach where only God is. Where not even the angels, without our permission, can enter. And there, to adore God, and praise Him, and address loving words to Him.
Guadalupe was very resistant, but she also had the ability to reflect, to "refract," every circumstance in her life towards God, beginning with her passion to improve and deepen in everything related to her profession. This was true right up to the end of her life. As someone close to her recounts about one of her final days, not long before she died: "One morning, when I entered her room, I saw that she was washing something in the sink. I asked what she was cleaning and she replied: No, I'm not cleaning anything. I'm carrying out tests on some textiles. I want to see how they react to certain stains."
With such great simplicity, Guadalupe joined the events of each day, her professional and human interests, to the Cross that was so evident in her life, never seeing herself as a victim. "How hard was Guadalupe's final agony! So brief and yet so long! Forty hours spent, as was her whole life, in a complete self-giving," her brother Eduardo recalls, who was at her side doing her final hours. But in the midst of all her suffering, her face was always filled with peace, with God.
Like the knots in a tapestry
Saint Josemaria once said in a large get-together: "My children, I'll tell you a bit about the experience of someone who spent ten years with a grave illness, without any hope for a cure, and who was happy, each day happier, because he abandoned himself in God's arms, convinced that God is not a distant being; He is even more than a good mother. When you (I'll remind that father, that mother, the two of you) when you take a knife or some matches out of a child's hands, the young boy will be upset, because you are hurting him by taking away a toy. We, with our earthly vision, always see the reverse side of the tapestry, the side with the knots, and we fail to realize that happiness comes later, that this life is passing as water passes between our hands. It is fleeting. Tempus breve est, the Holy Spirit says. We have very little time for loving. Tell them this on my part, on the part of someone who was sick, who was dying for years; even more, he died, but he's still around here, still battling. Insist to them that God in heaven is their Father and that the time for loving is short. They need to learn to love here! And love is shown in suffering."
Thus was the life of Guadalupe, one knot after another, until a marvelous tapestry was woven. Besides the passion for chemistry that she kept alive right to the end of her life, in 1968 she helped begin a School of Domestic Sciences, an innovative idea at the time. There she worked as assistant director and teacher of textiles. She continued carrying out an intense professional activity, despite all her growing physical limitations, until finally, in 1975, she had to go undergo another heart operation in the University of Navarra Hospital. She died a few weeks later, on the feast of Our Lady of Mount Carmel.
The material in the tilma of Our Lady of Guadalupe will probably always be a mystery. But it shows us clearly what God can do when he encounters a simple and good person like Juan Diego. The life of Guadalupe, made up of God's grace and love, shown above all amid suffering and illness, is yet another sign of his power to transform the life of simple souls docile to his action.
Antonio Schlatter Navarro
Zaragoza, December 12, 2016
Feast of Our Lady of Guadalupe
 In 2001, her process of canonization was opened. The Positio about her life and virtues is now with the Congregation for the Causes of the Saints.
 The quotes cited here are from the biography by Mercedes Eguibar,Guadalupe Ortiz de Landázuri. Trabajo, amistad y buen humor, ed. Palabra, Madrid 2001.