Museum security guards stood by nervously Thursday as curators -- joking they hoped the gem's storied curse wouldn't rub off -- allowed a reporter and photographer to hold the diamond briefly after it was removed from its case for scientific study.

What does it feel like to hold such a priceless gem, one of the most famed in the world?

The first thought that comes to mind is "Wow!"

It's like holding a bit of ancient India, the French Revolution, Georgian England and Gilded Age America in one magnificent moment.
You cradle the 45.5-carat stone -- heavier than its translucence makes it appear -- turning it from side to side as the light flashes from its facets, knowing it's the hardest natural material yet fearful of dropping it.

Once part of the French crown jewels, the fabled gem is now the star of the Smithsonian's National Museum of Natural History. It normally resides in a special protective display case in a secure room.

For the testing it was taken to a museum laboratory, reachable down winding corridors and through three locked doors. It was only the second time in 20 years the Hope has been removed from its necklace setting, where it is surrounded by bright clear diamonds that intensify its blue color.

National Gem Collection Curator Jeffrey Post ordered the lights turned off and focused an ultraviolet beam on the Hope Diamond. Then he switched off the beam and, in pitch dark, the diamond glowed bright orange-amber.

It's that strong color, which lasts for several seconds after the diamond is exposed to ultraviolet light, that intrigues scientists. What causes the gem to fluoresce remains a mystery. Post speculates it's related to chemical impurities that give it that blue color.

But the Hope Diamond has inspired legends over the years and some may prefer those to sheer science.

Some say, for instance, that the glowing color reflects the blood of royalty spilled in the French Revolution and the trail of bad luck said to have followed the stone over many years -- including the bankruptcy of the Hope family for whom it is named and the death of the young son of later owner Evalyn McLean.