Fancy color diamonds are chemically exactly the same as white diamonds, except for the inclusion of one or more other elements or compounds. The Hope Diamond, which is the most famous blue diamond in the world, gets its distinctive, stunning color through a high concentration of boron. Vivid yellow diamonds, such as the Tiffany Diamond, contain nitrogen. Anyone who’s seen Audrey Hepburn’s photo in promotional material for “Breakfast at Tiffany’s” has seen the absolutely scrumptious-looking stone. Some people still argue of which was more perfect, Audrey or the diamond.

Almost all fancy color diamonds can be found in the Los Angeles diamond district, even green. They’re the only colored diamonds not to be formed from the inclusion of another element. Rather, they come about when radiation affects their internal structure and are, thus, remarkably rare. The king of all fancy color diamonds is the carbonado. It’s black as a moonless, overcast night in the Brazilian rain forest, which is one of the only two places where these stones can be found. Black diamonds are a true puzzle, having been formed 300 million years after all other diamonds in the Earth’s crust.

There are many theories as to their origin. One of them pegs them as remnants from an exploding star thousands of light years from Earth; these shards of a stellar cataclysm then traveled across vast, intervening areas of space and, just by remote chance, fell to Earth. No diamond is more exotic and rare; only a total of 2.5 tons of stones have been mined in all of history. If you choose a diamond engagement ring whether white or fancy, round or any other shape, you’ll be giving your significant other an age-old piece of the universe that’ll signify the incredible depths of your love.