The ring, on sale at jeweler Hancocks in up-market Mayfair in London, has two 20-carat diamonds and coils around the finger with the ends of the band passing each other on top, according to UK media reports.
Because of the value of the diamond ring, Hancocks brought in a security guard specifically to guard the ring.
The Crossover ring was designed by Amy Burton as part of her Unum range. She told The Daily Mail that the ring is the only one of its design and size of diamonds on sale anywhere in the world.
Hancocks Managing Director Stephen Burton said: "The diamonds are extremely rare given they are a perfect match, having been cut from the same piece of rough diamond, and are truly exceptional.
"In my 40 plus years of working in the jewelry business, I have never seen a pair that are as large and well matched as these, having originated from the same rough diamond source which is incredibly rare."
