Brooklyn-based conceptual artist Jill Magid spent years plotting the perfect proposal—the location, the rock, the words—but what she had in mind was a bit different from most. On September 9 at the San Francisco Art Institute, Magid will exhibit a 2-carat diamond ring, created by compressing the cremated remains of Mexican architect Luis Barragán, to represent her proposal to the owners of his professional archive: open Barragán’s legacy to the public.

When the Pritzker Prize–winner died in 1988, his estate was divided between two close business colleagues. Barragán’s library became the museum Casa Luis Barragán—a UNESCO World Heritage Site since 2004. But the rights to the architect’s papers, drawings, and photographs have proved a more complicated matter. After Barragán’s beneficiary committed suicide in 1993, the archive was sold for a reported $3 million to Rolf Fehlbaum, chairman emeritus of his family’s furniture company, Vitra, and his wife, Federica Zanco, an Italian architectural historian. The couple shipped Barragán’s estate to Vitra’s headquarters in Birsfelden, Switzerland, where it has remained ever since, accessible only to Zanco, a few scholars, and an assistant.

Magid launched her investigation of Barragán in 2013, negotiating with his descendants and the Mexican government for a year before gaining access to the architect’s remains in 2015. This spring, she visited Zanco in Switzerland to explain her art project and to propose with the ring—a body of work in exchange for the body of the architect.

“You say it should go back to Mexico. Back to whom? Under what circumstances?” Zanco told The New Yorker, following her meeting with the artist in May. Though she has praised Magid and her project, Zanco remains protective of her rights to the work—and of its sanc­tity. She continued: “You agree [to allow people to use photos], and then you see them in a spread in a fashion magazine for something about how pink is the new color for spring.” Zanco has yet to accept Magid’s proposal.

Following the exhibition’s opening in Kunst Halle Sankt Gallen in Switzerland, The Pro­posal—which includes Magid’s documents and correspondence related to the project, as well as a video of the exhumation of Bar­ragán’s remains—will be on view at the San Francisco Art Institute through December 10.