Ruby, the July Birthstone

What Is the July Birthstone

I've handled enough red stones over the years to tell you the short version straight: ruby is July's birthstone. It's a red variety of the mineral corundum, and it gets that color from a trace of chromium. The name comes from the Latin ruber, which simply means red. It sits at 9 on the Mohs scale, and the finest reds carry a trade name you'll hear again and again, pigeon's blood.

Ruby Meaning and History

Most people meet ruby as a love stone, and that's fair enough. But the older story is bigger than romance, and it's the part I find more interesting.

Where Rubies Are Found

If you want to know where the great rubies came from, the answer for centuries was one place. Burma, now called Myanmar.

Myanmar and the Mogok Valley

The Mogok region has been turning out fine rubies for so long that "Burmese ruby" became shorthand for the best and most valuable rubies on the market. That's not marketing. The Carmen Lúcia Ruby, one of the finest large faceted rubies anyone knows of, came out of Mogok back in the 1930s. When a stone's birthplace becomes a quality grade all on its own, you know the ground was special.

Other Global Sources

The map has changed though. The ruby market shifted hard in recent years, mostly because of mining in Mozambique, and northern Mozambique near Montepuez is now the most productive ruby source in the world. Rubies turn up in other places too, among them parts of Southeast Asia and East Africa, but I'd be guessing if I ranked them by output, so I won't. Origin still drives value, and a documented source can move the price as much as the color does.

Ruby Color and Pigeon's Blood

Color is where ruby earns its name, so this is the section I'd read twice if you're shopping.

What Makes a Ruby Red

That red comes from chromium, the same trace element that pushes the color across a range from pinkish red to deep crimson. Chromium does something else worth knowing. It can make a ruby glow with a soft red fluorescence under the right light, and that inner fire is part of why a good Burmese stone looks lit from within rather than just painted red.

Pigeon's Blood Grade

You'll hear "pigeon's blood" thrown around, and it does mean something specific. It describes a pure red to slightly purplish red of a medium-dark tone, the kind whose color is lifted by that red fluorescence. The Burmese stones that hit this note are the ones the trade calls the finest, and the term has stuck for generations precisely because it's hard to improve on.

Ruby vs Pink Sapphire

Here's the part that trips people up. Ruby and pink sapphire are the same mineral, corundum, so the line between them is not a chromium percentage. There's no number you can point to. The call is made on color: red has to be the dominant hue before a stone gets to be a ruby, and if the color reads too light, it's a pink sapphire even when the color is strong. Pinpointing that dominant hue comes down to personal perception, which means two trained eyes can honestly disagree on the same stone.

Ruby Hardness and Durability

Ruby is tough, and that's a big reason it works in jewelry you actually wear. It ranks 9 on the Mohs hardness scale, second only to diamond among natural gems, with no cleavage plane to split along. Untreated ruby, and even heat-treated ruby, holds up to daily life in a way softer stones can't. If you've ever worn an opal ring and watched it scuff, you already understand why a ruby ring is a different proposition.

How to Care for Ruby Jewelry

Caring for ruby is mostly easy, with one real catch. Warm soapy water and a soft brush will handle ordinary wear without any drama.

Famous Rubies in History

A couple of named stones do a better job of explaining ruby's value than any chart I could draw. They also show why provenance matters so much.

The Sunrise Ruby is the one auction houses point to. It's a cushion-shaped Burmese ruby of 25.59 carats, set by Cartier between two diamonds, with no signs of heating and that prized pigeon blood color. Sotheby's sold it in Geneva in May 2015 and flagged the lot as a world record price for a ruby, around US$30 million.

That second stone lives at the Smithsonian, mined in Mogok in the 1930s and given to the museum in 2004. Put the two together and the lesson is plain. Size matters, but origin and rarity are what turn a fine ruby into a famous one.

Lab-Created Ruby Versus Natural

Sooner or later someone asks me whether a lab ruby is a real ruby. It is. A lab-created ruby is the same corundum colored by the same chromium, with the same Mohs 9 hardness and the same optical behavior as a natural ruby. Ruby was actually the first gem ever grown in a laboratory, with Auguste Verneuil's flame-fusion process announced back in 1902, and synthetic ruby is even said to have run through the very first working laser around 1960.

So the difference isn't authenticity. It's origin. A natural ruby formed in the ground over a long span of time and carries the rarity that comes with that, and that rarity, plus a documented source, is what opens the price gap with a lab stone that can be made on demand. A lab-created ruby can be a smart, honest choice for a buyer who wants the color and the durability without the natural-origin premium, as long as it's disclosed for what it is. If you want the full comparison of how a lab-created ruby and a natural ruby differ on heat treatment, value, and disclosure, that's its own subject worth reading on. The chemistry, to be clear, is not the thing that separates them.

Ruby Birthstone Jewelry