One of the more precious color details from Rep. Barney Frank’s wedding to Maine welder Jim Ready July 7 was the story of their wedding bands, described as black diamonds set in tungsten.

Ready, a regular companion of Frank’s at Washington social events, told the New York Times that he chose the welding material for the rings because “it helps keep me grounded, after going to lunch with the president.” Tungsten is also popular ring choice for same-sex couples.