Going for the Gold

Brazil is renowned for its hundreds of baroque churches laden with gold leaf. At one point, the country itself teemed with gold.

In the late 1600s, bandeirantes (settlers in colonial Brazil) discovered large deposits of gold and diamonds in present-day Minas Gerais (General Mines). The Portuguese colony would soon experience the longest gold rush in history and produce the largest gold mines in the world. Nearly a million people (including 500,000 enslaved Africans) would arrive in the region to mine.

One of the communities that flourished in that era was Catas Altas do Mato Dentro. In 1729, to accommodate the growing population, construction began on the Igreja Matriz de Nossa Senhora da Conceição (Mother Church of Our Lady of Conception). In line with other Brazilian baroque Catholic churches, this example features towering and intricately carved wooden columns, gilded altarpieces and motifs, and an array of sculptures and paintings.

“The carvings and decorative surfaces on the sculptures are of the highest quality,” says Stéphanie Auffret, a conservator with expertise in wooden gilded surfaces and senior project specialist at the Getty Conservation Institute (GCI). “These elements are reminiscent of the interiors of earlier churches in Europe, especially in Portugal.”

Unlike Portuguese churches, though, the Mother Church of Our Lady of Conception is part of a unique fusion of Portuguese, Indigenous, and African heritage. For instance, the Afro-Brazilian cultural practice known as Congado combines elements of Roman Catholic and African traditions through music, dance, and costume. And the interior of the church contains decorations finished with materials found in the surrounding forests.

One other detail sets the church apart. The ornate carvings that adorn its walls were worked on until the 1800s—when all construction abruptly stopped: the mining boom had come to an end, the church lost much of its parishioner base, and although listed as a historic site in the early 20th century by state and national organizations, it was abandoned.

In the early 1990s, Luiz Souza, now head of the Conservation Science Laboratory at the Federal University of Minas Gerais (UFMG), visited the church for his PhD thesis in chemistry. What he found was a time capsule. Sections of untouched, exposed wooden altars and sculptures remained inside the church, which was never finished, much less restored. Its interior had also been overrun by bats, birds, spiders, and “other regular inhabitants you find in dark and unventilated spaces,” he recalls.

Efforts to clean and restore the church have since brought it back to life, but much more remains to be done, especially in the broader region where many churches face similar challenges.

Sustainable Solutions

As part of GCI’s multiyear project Cleaning of Wooden Gilded Surfaces, Auffret and Rita Cavalcante, a chemist and conservator completing a three-year professional fellowship at the GCI, have been collaborating with UFMG to identify appropriate treatment options for the decorative surfaces commonly found in churches across Brazil. Last summer, to get a deeper understanding of preservation challenges in the region, the colleagues visited the Mother Church of Our Lady of Conception, 30 other baroque churches, and four museums across the Brazilian states of Minas Gerais, Bahia, and Pernambuco. They met with various caretakers, administrators, conservation professionals, and representatives from cultural and governmental organizations, such as the National Institute of Historic and Artistic Heritage (IPHAN).

Elaborate altarpieces, such as those in the Mother Church of Our Lady of Conception, entail a variety of techniques, including polychromy, chinoiserie, and the use of gold or silver leaf, onto which layers of colored glazes can be applied. When these glazes age, they darken and become highly sensitive to most cleaning systems.

Cleaning options for these surfaces often involve hazardous materials, and while they have evolved in recent decades to be safer and more sustainable, they are usually not accessible or affordable to conservation professionals in Brazil.

GCI researchers have been hard at work evaluating different cleaning methods, and fortunately, one system is showing promise in alleviating these issues. The team has been studying gels that not only clean gilded wood and other sensitive decorative surfaces but are also safe to use, easy to make, inexpensive to source, and environmentally friendly—making the gel cleaning system a sustainable option in more ways than one.

Greening the Cleaning

Developed by paintings conservator Matthew Cushman, the gels make use of polysaccharides, the most abundant carbohydrate in nature, and need only four base ingredients: water, agar or agarose, xanthan gum, and another polysaccharide extracted from certain plants, seeds, and even bacteria. The result is a thin gel that is transparent, extremely flexible, and can be placed on three-dimensional areas to soften dirt or grime for gentle removal. The GCI team has devised new formulations of these gels by adding greener organic solvents and cleaning solutions to allow the removal of overpaint or reduce darkened varnishes.

Some may recognize agar and xanthan gum as everyday baking and cooking ingredients. Polysaccharides are often used in face creams and masks. Cavalcante has worked with these before—not as a conservator, but during her 11-year stint as a chemist for a cosmetics company in Brazil.

An Artist and Scientist at Heart

Born and raised in a working-class neighborhood in São Bernardo do Campo, São Paulo, Cavalcante dreamed of studying art and having experiences beyond what her city could offer.

An affinity for science led her to study chemistry, a subject that provided local professional opportunities and helped her support her family. But she never forgot her earlier passion for art.

After a decade of working in the cosmetics field, Cavalcante left her job, moved to a new city, and immersed herself in a full-time conservation program at UFMG focused on movable cultural heritage. It was the perfect balance between chemistry and art. Once she’d completed her degree, she opened a studio specializing in paintings and polychromed wooden sculptures.

“During our trip in Brazil, I saw the beauty reflected in our cultural heritage but also the negligence of some of the churches we visited,” she says. “The laws in Brazil are exemplary—they give people the right to organize and demand the protection of heritage that is important to them—but they can only be fully applied when the population is educated on the significance of heritage and when more conservators occupy positions in public institutions.”

As she enters the final year of her fellowship, Cavalcante hopes to one day work in a university setting where she can continue to advance conservation research in Latin America. She sees her time at the GCI as a hopeful step in that direction.

“Being part of this project, under the guidance of highly qualified professionals, is without a doubt the most incredible experience I could have in the field of conservation,” Cavalcante says. “Everything I have been learning in these almost two years has given me the skills I need to develop my career in the direction I desire.”