A Jeweller’s Guide to Ruby: Identification Tips and Jewellery Making Advice

Welcome to the dazzling and fiery world of ruby! With its rich, vivid red hues ranging from pinkish-red to deep crimson, ruby has captivated jewellers and collectors for centuries. As one of the most valuable and sought-after gemstones, ruby is synonymous with passion, power, and luxury.

Let’s explore everything you need to know about this remarkable gem.

Basic Identification Information

Name & Synonyms:
Ruby; often referred to as "pigeon’s blood" ruby for the finest deep red varieties.

Species:
Corundum

Colour Range:
Pinkish-red to deep red, with the most valuable stones displaying a strong, saturated hue with minimal secondary tones.

Refractive Index:
1.762–1.770

Birefringence:
0.008–0.010 (+0.009, -0.005)

Optical Sign:
Uniaxial-

Specific Gravity:
3.95–4.10

Fluorescence:
Usually strong red (especially under UV light), particularly in high-quality Burmese rubies.

Lustre:
Vitreous (bright and glass-like when polished).

Clarity:
Type II
Usually contains some inclusions, such as rutile silk, which can enhance the stone’s appearance by creating a soft glow. Eye-clean rubies are very rare and highly valuable.

Gems often mistaken for ruby:
Red spinel, red garnet, red tourmaline.

Mohs Hardness:
9

Wearability:
Excellent; one of the hardest gemstones, highly suitable for daily wear.

Birthstone:
July

Common Treatments

Most rubies undergo some form of treatment to enhance their colour and clarity. The most common treatments include:

• Heat treatment - a standard in the industry, improving colour and dissolving silk inclusions to enhance the gemstones clarity.
  
  
• Diffusion treatment - enhances surface colour but is not considered natural enhancement.
  
  
• Oiling or fracture-filling - less common but done to improve clarity.
  
  
• Lead-glass filling - A common treatment for poor quality stones. Glass filled rubies are considered a separate gemstone due to the amount of glass often used and as such it should always be disclosed.

Some treatments can be quiet difficult to detect but glass filled rubies are relatively easy to identify with a microscope. You should look out for gas bubbled and a tell-tale shimmer that's usually orange or blue where the glass and the ruby join. 

Durability Considerations

Ruby is one of the toughest gemstones, second only to diamond in hardness. It resists scratches from everyday wear, making it ideal for rings and other frequently worn jewellery.

However, lead-glass-filled rubies are significantly less durable and should be treated with care as they can fall apart if exposed to chemicals or knocked too hard.

Jeweller’s Setting Tips

• Bezel settings provide excellent protection while enhancing the deep red hue.
  
  
• Prong settings work well but should be positioned carefully to secure the gem without placing excessive pressure on delicate corners to help prevent chipping the gemstone.
  
  
• Rubies can withstand most heat exposure, although care should be taken with included stones as the inclusions can't always withstand the heat.
  
  
• Lead-glass-filled rubies should never be heated, soldered near, or cast in place.
  

Care Instructions

To clean ruby jewellery, use warm, soapy water and a soft brush to gently remove dirt and debris.

Ultrasonic and steam cleaners are generally safe for untreated and heat-treated rubies but should be avoided for fracture-filled or diffusion-treated stones, as these treatments can make the gem more vulnerable to damage.

When storing ruby jewellery, keep it separate from diamonds and other harder materials to prevent scratches.

Aesthetic & Design Insights

Ruby’s rich red hue makes it an ideal centre stone for high-end jewellery. It pairs beautifully with various metals:

Yellow gold enhances its warmth, creating a regal, timeless look.

White gold and platinum provide a striking contrast, making the red appear even more intense.

Rose gold complements ruby’s pinkish tones, creating a soft and romantic aesthetic.

Rubies also pair well with other gemstones, such as diamonds, sapphires, and emeralds, for bold and elegant combinations.

Market & Ethical Notes

Fine-quality rubies are among the most valuable gemstones per carat, often surpassing diamonds in price. Burmese rubies from Myanmar (Mogok region) are considered the finest, but rubies are also found in Thailand, Sri Lanka, Mozambique, and Madagascar.

Ethical sourcing is a significant concern in the ruby trade, particularly regarding conflict stones from Myanmar. Many jewellers now seek ethically sourced rubies from certified mines in Africa and other regions.

Synthetic, lab-grown rubies provide ethical and affordable alternatives without the environmental and social concerns associated with mining.

Symbolic & Spiritual Meanings

Ruby has long been associated with power, passion, and protection. In ancient cultures, it was believed to bring vitality, courage, and prosperity. Warriors in Burma and India embedded rubies in their armour, believing they granted invincibility in battle.

In modern crystal healing, ruby is considered a stone of energy, love, and confidence, said to stimulate the heart chakra and enhance motivation.

Etymology

The name "ruby" comes from the Latin word ruber, meaning "red."