Apple CEO Tim Cook met with Pope Francis in the Vatican on Friday

A peek at the schedule of Pope Francis has revealed that the head of the Catholic Church met with Apple Chief Executive Tim Cook on Friday, though what the two discussed remains a mystery.

Carol Glatz of the National Catholic Reporter snapped a picture of the Pope's schedule on Friday, revealing that the pontiff had a meeting scheduled with Cook at 11:30 a.m. local time. Tom Cheshire of Sky News later confirmed that the meeting took place, as highlighted by Business Insider.

Cook's meeting with His Holiness comes one week after Pope Francis met with Eric Schmidt, CEO of Apple rival Alphabet.

What Cook and the Pope discussed remains unknown, but both are known as fierce advocates for the environment and equality. Last year, Cook was the recipient of the Robert F. Kennedy Human Rights "Ripple of Hope" award, recognizing people who "demonstrate commitment to social change and reflect Robert Kennedy's passion for equality, justice, basic human rights, and his belief that we all must strive to 'make gentle the life of this world.'"

Though Cook hasn't discussed his personal thoughts on religion in depth, he did mention God in an open letter published in 2014, in which he publicly revealed his sexual orientation.

"I consider being gay among the greatest gifts God has given me," Cook wrote.

While a sit-down with a religious leader is unique for a tech CEO, high-profile meetings are the norm for Cook, who frequently meets with elected officials and has even testified before Congress. Cook's celebrity status even garnered him an appearance on Stephen Colbert's "Late Show" last September.