Ruby has long been called the “King of Gems.” Across cultures, it symbolizes passion, protection, vitality, and power. Ancient Burmese warriors believed rubies made them invincible. European royalty prized them as stones of authority and divine favor.

Unlike emerald’s quiet glow, ruby burns. It commands attention with a saturated red that feels alive.

1. Ruby’s Mineral Properties

Ruby is the red variety of corundum (the same mineral family as sapphire).

🔬 Chemical & Physical Properties

• Mineral family: Corundum

• Chemical formula: Al₂O₃

• Color source: Chromium (Cr)

• Hardness: 9 on the Mohs scale

• Crystal system: Trigonal

• Refractive index: ~1.76–1.77

Corundum’s hardness (second only to diamond) makes ruby highly durable for daily wear — far more resilient than emerald.

2. Defining Features of Ruby

🔥 1. Color — The Ultimate Value Driver

Color determines almost everything in ruby pricing.

The most desirable ruby color is often described as:

“Pigeon Blood Red”

• Vivid, highly saturated red

• Slight bluish undertone

• Strong fluorescence

• Medium tone (not too dark)

If too dark → appears brownish.
If too light → leans pink (and may be classified as pink sapphire instead of ruby).

Fine rubies have a glowing internal fire, especially under sunlight due to chromium fluorescence.

🔎 2. Clarity — Expected but Controlled

Rubies commonly contain:

• Rutile “silk”

• Mineral crystals

• Growth zoning

• Small fractures

Unlike emerald (Type III), ruby is typically considered Type II — inclusions are common but not always prominent.

Interesting note:

• Fine silk can actually enhance glow.

• Too much silk reduces transparency.

• Oriented rutile needles can create a star ruby (asterism) when cut as cabochon.

Eye-clean rubies above 2–3 carats are exceptionally rare — and priced accordingly.

3. Common Treatments

Most rubies on the market are treated. The type of treatment significantly impacts value.

🔥 1. Heat Treatment (Most Common)

• Improves color

• Enhances clarity

• Stable and widely accepted

Heat-treated rubies are still considered natural.

💎 2. Glass-Filled (Lead Glass) Rubies

• Fractures filled with glass

• Dramatically improves appearance

• Significantly lowers value

• Fragile and vulnerable to damage

These are commercial-grade stones and should be clearly disclosed.

🧪 3. Flux-Healed / Lattice Diffusion

• Less common but possible

• Impacts pricing and transparency

For significant purchases, a lab report from organizations like Gemological Institute of America (GIA) is essential.

4. Key Factors That Determine Ruby Price

Ruby is often the most expensive colored gemstone per carat, sometimes exceeding diamond prices at the top tier.

1. Color (50–70% of Value)

• Pure vivid red commands the highest premium

• Strong saturation is critical

• Slight bluish undertone preferred

• Avoid brownish or overly dark tones

Top Burmese “pigeon blood” rubies are the benchmark.

2. Origin

Origin significantly influences perception and pricing:

• Myanmar (Burma) – historically most prestigious

• Mozambique – increasingly important source of fine rubies

• Thailand – typically darker stones

While origin alone doesn’t determine quality, Burmese stones often command a premium due to history and color profile.

3. Clarity

• Eye-clean stones are rare

• Transparency matters more than microscopic perfection

• Large fractures reduce value

4. Carat Weight

Ruby prices increase exponentially with size.

• Fine 1 ct ruby → already rare

• Fine 3 ct ruby → extremely rare

• Fine 5+ ct untreated ruby → auction-level stone

High-quality rubies above 5 carats are among the rarest gems in the world.

5. Treatment Level

• Untreated rubies with fine color = highest premium

• Heat-treated = market standard

• Glass-filled = significantly lower value

Treatment disclosure is critical to ethical pricing.

Practical Buying Advice

If selecting a ruby:

✔ Prioritize color above all
✔ Look at the stone in natural daylight
✔ Avoid overly dark stones that “black out”
✔ Ask about treatment
✔ For larger stones, request a lab report

Because ruby is durable (hardness 9), it works beautifully for:

• Engagement rings

• Right-hand statement rings

• Everyday luxury pieces