Here's a fact that surprises almost every guest on our tour: the diamond in an engagement ring is usually far older than the dinosaurs. Many natural diamonds formed between one and three billion years ago. Dinosaurs first appeared about 230 million years ago, which makes them newcomers by comparison.
So how does something that ancient end up in a small office on West 47th Street? Here's the incredible journey, in five stops.
Stop 1: Deep inside the earth
Natural diamonds form roughly 100 miles below the surface, where heat and pressure are intense enough to squeeze carbon atoms into a crystal. Diamond is pure carbon, the same element as pencil graphite. The difference is simply how the atoms are packed together, and that packing makes diamond the hardest natural material on earth.
Stop 2: A volcanic express ride
Diamonds didn't crawl to the surface. They were carried up quickly by rare, deep volcanic eruptions that punched through the earth's crust. These eruptions left behind carrot-shaped pipes of rock called kimberlite. That's where many of the world's diamond mines are found today, in places like Botswana, Canada, Russia and South Africa.
Stop 3: The mine
Even in a rich mine, diamonds are rare. Tons of rock are processed to find a small amount of rough diamond. Rough diamonds don't sparkle yet. Many look like cloudy pebbles or small frosted crystals. It takes a trained eye to see the gem inside.
Stop 4: The cutter's wheel
This is where human skill takes over. A cutter studies each rough stone to plan the best possible shape. Then it's sawn, shaped and polished, facet by facet, often losing around half its original weight in the process. A classic round brilliant has 57 or 58 tiny, precisely angled facets. Get the angles right and the stone blazes with light. Get them wrong and even a large diamond looks dull.
Stop 5: 47th Street
From cutting centers around the world, many polished diamonds make their way to New York's Diamond District, one of the most important diamond hubs in the United States. Here they're traded, graded, recut and set into jewelry, often within a few buildings of each other.
Why kids (and grown-ups) love this story
This is one of the most family-friendly parts of our tour. Children are amazed that they can hold something older than a T. rex. Adults are usually surprised by how much craftsmanship goes into a stone they've worn for years without a second thought.
See the journey up close
On The New York Tour of Diamonds, Hemant brings this journey to life right on 47th Street. In 90 minutes you'll learn how diamonds form, see how they're cut and polished, hold a real diamond with tweezers, look through a jeweler's loupe and watch how a diamond is set into jewelry.
- Where: West 47th Street between Fifth and Sixth Avenues, a short walk from Rockefeller Center and Times Square.
- When: three tours a day, Monday to Friday.
- How long: 90 minutes.
Quick answers
Are lab-grown diamonds also billions of years old? No. They're real diamonds, but they're grown in weeks in a lab. We'll explain the difference on the tour.
Is the tour good for children? Yes. Curious kids love the loupe and the "older than dinosaurs" fact.
Do I need to know anything about diamonds? Not at all.
Planning a fall visit with family or friends?
Give your trip a story nobody else back home will have. Book The New York Tour of Diamonds ahead of your visit and hold a piece of ancient earth in your hand.