The world famous Hope Diamond and Wittelsbach-Graff Diamond were not cut from the same stone, a National Gem Collection statement said. The latter is part of the Smithsonian Institution.

According a statement by Jeffrey Post, the National Gem Collection's curator, quoted by the Seattle Times, "there is an uncanny resemblance (between the blue diamonds), but they are different. They are not part of the same crystal or rough.”

The two blue diamonds were examined under a variety of microscopes and lights at the Smithsonian to try and solve the centuries-old mystery of their possible-common origin. The Hope Diamond weighs 45.52-carats and the Wittelsbach-Graff Diamond weighs 31.06-carats. Both gemstones have a deep blue color.

The National Gem Collection had the opportunity to probe the diamonds after the Wittelsbach-Graff Diamond, which has not been on public display for more than 50 years, was lent to the Smithsonian for display, alongside the Hope Diamond.

"The tests supported the fact that they are extremely similar, in their color, in the way they phosphoresce. It's amazingly similar," Post said, adding that at the same time, the differences between the two blue diamonds became apparent under a diamond-view microscope. "The detailed pattern is different in the two," he said.