Rich, regal, and deliciously indulgent, ruby is that velvety, dark cherry red you can almost taste. One of only four precious gemstones, ruby has been a royal favorite for centuries — a stone that looks just as at-home in the crown jewels as it does in a ruby engagement ring or treat-yourself ring you'll wear every day. There’s a drama and a richness to ruby that gives true atop-the-throne energy.
If you’ve been traipsing through the Gem Breakfast universe lately, you’ve seen the glossy candy-apple rubies from Zahn-Z Fine Jewelry and Made by Gem Breakfast: interlocking, deeply saturated red ruby hearts wrapped in buttery 14k gold, alongside gleaming heirloom bands with hand-engraved stars, hearts, and star-set round rubies. They feel lavish and lived-in at the same time — proof that ruby can be deeply decadent and still made for everyday wear.
Keep reading for your complete guide to ruby, including:
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What is ruby?
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Ruby color
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Ruby meaning
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How to choose a ruby: the 4Cs
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Ruby treatments
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Durability of ruby
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Ruby vs sapphire vs spinel vs garnet
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All your ruby questions answered
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Where to buy ruby jewelry
Ruby at a glance
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What it is: Red corundum (same mineral family as sapphire)
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Hardness: 9/10 — excellent for everyday wear
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Best feature: Intense, glowing red color + natural fluorescence (“inner fire”)
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Best for: Engagement rings, heirloom pieces, and statement rings
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Watch-out for: Treatments (especially glass-filling), very dark stones, uneven color
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Price: Can be approachable — or eye-watering — depending on color, size, and treatment
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Vibe: Heart-led and unapologetic
If you love ruby but not the price: look at red spinel or certain red garnets
WHAT IS RUBY, REALLY?
Ruby is the red variety of corundum, the same mineral family as sapphire. When corundum shows up in red, we call it ruby. In every other color — blue, yellow, green, purple, or even pink — we call it sapphire.
So yes — ruby and sapphire are essentially the same, except one is red and the other spans the rest of the rainbow. Ruby is also a bit rarer, as deep red corundum is tough to find.
Why rubies are red
Just like with sapphires, rubies are created when a tiny dose of another mineral mixes with corundum. In ruby’s case, that extra mineral is chromium. Just a tiny drop of chromium will create a pink sapphire, but a touch more will bring forth that rich red ruby tone.
Chromium doesn’t just make ruby red though — it can also make the stone fluoresce (glow slightly) in sunlight. That’s why some high-quality rubies look like they’re lit from within, especially outdoors. When you see that subtle inner fire, that’s the chromium at work.
The balance of elements matters, too. Rubies with more iron can read darker or more brownish/purplish rather than true red and will also have less of that fluorescence than the purest red rubies.
Read our Guide to Sapphire to learn how all the other colors of corundum are formed.
WHY WE LOVE RUBY
Built for real life
At a 9 on the hardness scale, ruby is second only to diamond. That’s why ruby engagement rings have been a go-to for centuries. It can handle your everyday life and be passed down for generations to come.
Pure presence
Ruby has that saturated, smoldering, poison apple energy. Mysterious and completely delicious.
Royal, but make it wearable
Rubies have lived in crown jewels and heirloom collections for centuries, and somehow still feel completely at home in a ring you wear every day.
That inner glow
Many rubies naturally fluoresce in daylight, giving them that soft, luminous glow that gives extra life to an already incredible stone.
The trade-offs to know
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Price rises quickly as size and color improve
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Treatments are common - avoid anything beyond regular heat treating
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Some rubies look amazing in store lighting but fall flat at home
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Many rubies are too dark or slightly brownish in real life
In other words: ruby is magical, but you want to choose carefully.
Meaning of ruby
Ruby carries heat. The deep, saturated red feels warm and alive — it has a pulse to it that pulls you out of your head and back into your body.
For centuries, people have reached for ruby in moments that called for strength. It’s been worn as a sign of courage, protection, and resolve. Whether you care about gemstone lore or not, there’s something steady about ruby; it holds its ground.
In a ring, ruby feels intentional. After all, red is never accidental.
HOW TO CHOOSE A RUBY — THE 4 CS
1) Color (always first)
If you take one thing from this guide, let it be this: color comes before everything. A smaller ruby with incredible color will almost always outshine a bigger one with meh color.
Color in ruby comes down to three things — hue, tone, and saturation.
Hue — what kind of red?
Rubies live on a spectrum. Some are a touch purplish red, some lean a little orangey, and a very small number are close to pure red. There’s no single “right” shade — it’s about what you love most:
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Pure red — rare, and usually the most valuable
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Slightly purplish red — common and often really beautiful
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Slightly orangey red — warmer, and stunning in yellow, peach, or rose gold
What to watch out for:
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Reds that drift brown (they can look flat or dull in real life)
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Stones that read more pink than red (visually, you’re now in pink sapphire territory, which we also love but not if you’re shopping specifically for rubies)
Tone — how light or dark it is
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Too light: can feel less like “ruby” and more like bright pink
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Medium tone: usually the goldilocks tone — rich but lively
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Too dark: can look inky, maroon, or almost black in low light
If you have to squint to see the red, the tone is probably too dark.
Saturation — how vivid it is
This is what gives ruby its intensity. A highly saturated ruby looks rich and unmistakably red. Lower saturation can make a stone feel washed out or slightly dull/greyish.
A helpful test: look at the ruby in different lighting — daylight, indoor warm light, and cloudy light. If it stays stunning across all of them, you’ve got a good one.
Finding your red: Some rubies are bright and glowing. Some are deep and velvety. Some lean a touch purple, some a touch orange. The best ones feel rich, alive, and clearly red in real life — not just under bright indoor lights.
2) Clarity — what’s normal + what to avoid
Clarity is a measure of inclusions — the little internal features that form inside a gemstone as it grows. In rubies, these can look like tiny fractures, needle-like lines, mineral crystals, or cloudy areas. They’re part of how natural rubies are formed.
GIA groups gemstones into three types based on how likely they are to contain inclusions in nature:
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Type I gems rarely have visible inclusions
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Type II gems usually have some inclusions
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Type III gems are almost always included
Rubies fall into Type II, which means inclusions are common and totally normal. The goal with ruby clarity isn’t perfection. It’s to avoid anything that interferes with the color or the structure of the stone.
What to watch out for:
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Large cracks that reach the surface
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Inclusions that make the stone look cloudy, patchy, or lifeless
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Heavy glass filling (we’ll get into this in the Treatments section)
One more thing worth knowing: the more vivid the color, the more inclusions tend to “disappear” to your eye. A deeply saturated ruby can hide a lot. And in some cases, inclusions can actually add character — certain needle-like inclusions can create a soft silkiness or even a star effect in cabochon rubies, which can be really beautiful.
3) Cut — why this matters so much
Cut is where a lot of rubies make or break themselves. A poorly cut ruby can look dark, sleepy, or uneven — even when the color is stunning. A well-cut ruby, on the other hand, feels bright, balanced, and alive across the whole face of the stone.
A good ruby cut should:
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Look bright across most of the stone
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Avoid a dark “hole” or window in the center
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Show color evenly when viewed face-up
Great ruby cutting is rarer than people realize — and it’s one of the biggest reasons two rubies with similar color can look completely different in real life.
Shape and cutting choices
Rubies don’t grow in neat little perfect blocks, so cutters often have to make trade-offs between beauty and carat weight. That’s why you’ll see a lot of ovals, cushions, and pears in ruby — these shapes usually help preserve color and yield more weight from the rough.
More angular shapes like emerald cuts can look incredible as rubies, but they’re harder to pull off well. If the proportions aren’t right, they can show color zoning or go dark in the center.
Cabochon (smooth, domed) cuts are common for certain rubies — especially star rubies or stones with silk — because they showcase texture and light effects rather than sparkle.
Light, symmetry, and evenness
For a faceted ruby, symmetry and even light distribution matter just as much as shape. Facets that are uneven, lopsided, or poorly aligned can make a ruby look patchy or dull.
When the cut is done well, light moves through the stone in a way that brings out depth, glow, and that signature ruby richness instead of swallowing it.
In short: color may be king, but cut is the reason you actually get to see it.
4) Carat — size vs quality
Rubies come in all sizes, but prices rise quickly as carat weight increases — especially when the color is deep and saturated.
Truly vivid, well-cut rubies over one carat are uncommon, and over two carats they can become very expensive, very quickly. Fine untreated rubies over one carat with vivid color are among the rarest colored gemstones in the world.
Because of that, most people end up making the same trade-off: smaller stone, better color. A half-carat ruby with deep, glowing red will usually look more impressive than a larger stone that’s darker or washed out. With ruby, quality almost always beats size.
For a ruby engagement ring, many people land between 0.5–2 carats, depending on budget and aesthetic. Some go smaller to prioritize color, others choose size and accept a slightly different shade of red. Both are valid — it just comes down to what you love.
TYPES OF RUBIES
Faceted rubies (the most common)
These are the rubies you’ll see in most rings - faceted and high sparkle. Ovals and cushion cuts are common because they tend to hold color well and make efficient use of the rough. Emerald cuts can look striking, but they’re harder to pull off in ruby and the color can look uneven if the cut isn’t exactly right. Antique cuts like old mine or rose cuts feel softer and moodier, with less sparkle and more soul.
Star rubies (asterism)
Some rubies show a visible star across the surface — called asterism — created by aligned needle-like inclusions inside the stone. Because of this, star rubies are usually cut as cabochons (smooth, domed shapes) rather than faceted.
A great star ruby has a clear, centered star that glides smoothly as the stone moves in the light.
“Silky” vs clean rubies
Many rubies contain very fine, needle-like inclusions known as silk. Sometimes this silk gives the stone a soft, velvety look. Other times, it can make the ruby appear slightly hazier or less transparent.
Durability of ruby
Gemstones are rated in four areas for durability:
Hardness – resistance to scratches: Ruby (corundum) rates a 9 on the Mohs scale, making it one of the hardest gemstones used in jewelry. That puts it in the “very durable for everyday wear” category — only diamond is harder.
Toughness – resistance to breakage: Ruby has excellent toughness, meaning it resists chipping and cracking well under normal wear. This is one of the reasons rubies have been used in engagement rings for generations.
Cleavage / parting – how a stone splits when struck: Ruby has no true cleavage, so it doesn’t tend to split cleanly along planes the way some gemstones do. Corundum can show “parting” in certain directions, but in everyday jewelry wear this is rarely a concern — the bigger thing to watch is sharp corners or exposed edges, especially in angular cuts.
Stability – how it handles light, chemicals, temperature, and humidity: Under normal wearing conditions, ruby is considered very stable. It holds up well to light, heat, and most everyday chemicals.
Caring for ruby jewelry
To keep your ruby gemstone looking its best, follow these cleaning and care tips:
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Clean ruby jewelry with warm, soapy water and a soft toothbrush.
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Ultrasonic or steam cleaning is usually fine for untreated or heat-treated rubies — avoid these if your ruby is heavily glass-filled or dyed.
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Store ruby jewelry separately to prevent rubbing against other pieces (especially diamonds or other very hard stones).
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Remove ruby jewelry before intense physical activity or rough work to protect both the stone and the setting.
Read our blog How to Care for Fine Jewelry for more.
RUBY VS OTHER RED GEMSTONES
Ruby vs Pink Sapphire
Ruby and pink sapphire are the same mineral (corundum) — they just live in different spots on the red-to-pink spectrum. The line between them isn’t perfectly fixed, which is why one lab might call a stone ruby while another calls it pink sapphire.
If you’re choosing between them, it usually comes down to tone. If you want unmistakable red, opt for ruby. If you’re leaning softer or more pink-forward, sapphire is it. The durability is identical — it’s purely which color calls to you.
See our favorite pink sapphire rings here →
Ruby vs Red Spinel
Spinel can look very similar to ruby, especially in saturated reds. It’s a different mineral (hardness 8 vs. ruby’s 9), so still durable — just a touch softer.
Spinel is often untreated, which many people love, and it can be found in vivid ruby-esque reds without the dramatic price jump you’ll see with larger rubies.
If you want that deep red, ruby-like energy without ruby prices, red spinel is worth a look.
Curious about spinel? Snack on our full guide to red spinel here →
Ruby vs Garnet
Garnet shows up in a wide range of reds — from bright raspberry to deep wine and brick tones. It’s a different mineral family entirely and is softer (6.5–7.5), which makes it better suited for rings you rotate in rather than a ruby engagement ring you never take off.
If durability matters most, ruby's your girl. If it’s the color you’re after, garnet brings the red without the ruby-level price climb.
RUBY VS RUBELLITE
Rubellite is the red-to-pink variety of tourmaline — saturated, juicy, and often mistaken for ruby at first glance. The color can be close, but the mineral isn’t the same.
Rubellite usually leans a little more pink or electric in color, and it’s softer than ruby (7–7.5 vs. 9), which matters if you’re choosing a ruby engagement ring or wear-everyday just-because ring.
If you love vibrabt red but aren’t married to rubies, rubellite might surprise you in the best way.
Curious about tourmaline? Read our full guide here →
LAB-GROWN VS NATURAL RUBY
Lab-grown rubies are made of the same mineral as natural rubies (corundum) — they’re just created in a lab instead of forming in the earth.
In general, lab-grown rubies tend to be:
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More affordable than natural rubies
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Very high in clarity, often appearing nearly flawless
If a ruby is lab-grown, it should always be clearly disclosed as such.
When it comes to ethics, “lab-grown” isn’t automatically better or worse. Some labs have strong labor and environmental standards — others don’t. The same is true of mines. In both cases, ethics come down to the specific operation, not the category of stone.
Because lab-grown rubies aren’t rare and can be reproduced, they also don’t tend to hold value in the same way natural rubies do. Natural rubies, on the other hand, are valued for their rarity, character, and the way they form deep within the earth under intense heat and pressure over millions of years — which is why we work exclusively with natural rubies at Gem Breakfast.
RUBY TREATMENTS
Heat treatment (normal)
Most rubies you’ll see on the market have been heat-treated to improve color or clarity. This is standard practice in the gem world and has been for decades. A heated ruby is still a natural ruby.
That said, truly unheated rubies are much rarer, which is why they usually come with a higher price tag.
Diffusion treatment
Diffusion treatment alters a ruby’s color by forcing additional elements (like beryllium) into the surface of the stone under very high heat. Unlike traditional heat treatment, which enhances what’s already present throughout the crystal, diffusion only affects the color of the outer layer.
If a diffused ruby is chipped, scratched, or repolished, that surface color can be reduced or removed, revealing a lighter or less aesthetic body color underneath. Because of this, diffused rubies are typically worth much less than untreated or heat-treated stones.
It also requires full disclosure. Without it, a diffused ruby can look far more valuable than it actually is. We don’t work with diffused rubies at Gem Breakfast.
Lead-glass filling
Some heavily fractured rubies are filled with high-lead glass to improve clarity. The glass seeps into surface-reaching cracks and makes the stone look cleaner and more transparent than it naturally is.
The issue? The glass is not ruby. It has very different physical properties. That means the stone can be more sensitive to heat, chemicals, and even standard jewelry repair. Resizing, retipping prongs, or future polishing can damage the fill. Over time, the glass can also become cloudy or degrade.
Because so much of what you’re seeing is filler rather than ruby, these stones are valued far lower than natural or simply heat-treated rubies.
We don’t work with lead-glass filled rubies at Gem Breakfast.
Your ruby questions, answered
What is the July birthstone?
Ruby is the official birthstone for July — a durable, precious red gemstone associated with passion, vitality, and the heart.
Are all rubies treated?
Most rubies on the market are heat-treated to improve color and clarity, and this is widely accepted in the trade. Unheated rubies exist, but they are rarer and usually more expensive.
What is the best ruby color?
The most coveted ruby color is a vivid, medium to medium-dark red with strong saturation and minimal brown or gray undertones. Color matters more than size or clarity.
What does “pigeon blood” ruby mean?
“Pigeon blood” is a trade term used to describe very vivid red rubies, often with strong natural fluorescence. It is not a regulated or standardized grade.
Are rubies good for engagement rings?
Yes. With a Mohs hardness of 9, ruby is one of the most durable colored gemstones for daily wear and a great choice for engagement rings or wear-every-day rings.
How much does a ruby cost?
Ruby prices vary widely based on color, size, clarity, and treatment — from relatively accessible to extremely high-end. Vivid color and larger sizes drive prices up fastest.
Does ruby origin matter?
Origin can affect price and reputation, but it doesn’t guarantee beauty. In practice, color, cut, and treatment usually matter more than where a ruby came from.
How can you tell if a ruby is real?
Real rubies are made of corundum and rank 9 on the Mohs hardness scale, making them very resistant to scratching. Most natural rubies contain inclusions, while synthetic or imitation stones often appear overly flawless or show curved growth lines under magnification. The most reliable way to confirm authenticity is through a gemological laboratory report that identifies whether the ruby is natural, lab, synthetic, or treated.
Ruby vs sapphire: which is more expensive?
Ruby and sapphire are the same mineral (corundum), but fine ruby is generally rarer — especially in vivid red colors. Because of this, high-quality rubies often have higher prices per carat than most sapphires. However, pricing depends on color, size, clarity, and treatment.
Where to buy ruby jewelry
If you’ve ever peeked into the Gem Breakfast kitchen, you’ve probably already seen a few ruby treats come out of the oven — from one-of-a-kind rings by our independent designers to our own Made by Gem Breakfast creations. We like our rubies rich, lively, and with a one-of-one twist.
Craving one for yourself (or someone lucky)? Browse our ready-to-ship ruby engagement rings orbook a free custom consult and we’ll dream something up together.
See you in the kitchen!