Ruby – the noble gemstone

Ruby – What is this noble gemstone?

Chemical composition and crystallographic structure

Ruby is a variety of corundum (mineral with the chemical formula Al₂O₃ – aluminum oxide), whose red color comes from the presence of chromium (Cr³⁺). Depending on the amount of chromium and other trace elements (e.g., iron or vanadium), the hue can vary slightly – from pinkish to purplish red.

• Crystal system: trigonal

• Mohs hardness: 9 (second only to diamond)

• Density: 3.97–4.05 g/cm³

• Luster: vitreous

• Fracture: conchoidal

• Color: from pinkish-red to deep red

Fluorescence

Many natural rubies exhibit intense fluorescence under ultraviolet light, which enhances their color saturation and is used for authentication purposes.

Global occurrence of rubies

Rubies are found in many regions worldwide, but the most highly prized rubies come from Myanmar (formerly Burma), especially from the Mogok region, known for their “pigeon blood” color – a saturated deep red with a bluish undertone.

Main ruby-producing locations:

• Myanmar (Burma) – finest quality stones

• Thailand – darker, brownish-red tones

• Sri Lanka – lighter, pinkish rubies

• Mozambique – bright red rubies with high commercial value

• Madagascar, Tanzania, Afghanistan – new discovery sources

Use of ruby in jewelry

Rubies have been set in rings, earrings, necklaces, and brooches for centuries. Their hardness makes them extremely durable, ideal for daily wear, especially in engagement rings and heirloom jewelry.

Industrial applications of ruby

Synthetic rubies are used beyond the jewelry industry:

• in laser technology (the first working laser was based on synthetic ruby),

• in watchmaking – ruby bearings (reduced friction),

• in optics and scientific instruments.

Symbolism and esoteric meaning

In both Eastern and Western cultures, ruby has long been seen as a stone of life and energy, often attributed with protective properties. It was used as a talisman against misfortune and to foster courage, willpower, and love.

Commonly attributed esoteric properties of ruby:

• Enhances life energy (prana)

• Activates the heart and root chakras

• Amplifies passion, love, and sexuality

• Encourages bold decision-making

• Protects against negative psychic influences

Synthetic rubies and imitations

The first synthetic rubies were produced using the Verneuil process in 1902. Today, more advanced synthesis methods exist, including the Czochralski process, hydrothermal growth, and zone melting. While synthetic rubies may look nearly identical to natural ones, they differ in internal structure and market value.

Numerous ruby imitations are also found on the market:

• synthetic spinel (often mistaken for ruby),

• red-colored glass,

• garnets and other red minerals.

Interesting facts about rubies

• The largest natural ruby is the “Neelanjali Ruby,” weighing over 1,370 carats.

• The largest cut ruby is the “Liberty Bell Ruby” (notorious for being stolen).

• In ancient Burma, warriors believed rubies made them invincible in battle.

• In Indian tradition, ruby was considered the "king of gems" (ratnaraj) and reserved for the highest castes.

Conclusion

Ruby is an exceptionally valuable and symbolic gemstone with a rich history, outstanding physical properties, and profound cultural significance. Whether as a decorative gem or esoteric tool, it remains one of the most sought-after stones in jewelry and gemstone collecting.