Ruby — The Complete Guide

Ruby is the king of coloured gemstones — the most valuable variety of corundum, prized for its vivid red colour, exceptional hardness, and one of the longest histories in fine jewellery of any gemstone. From the legendary "pigeon's blood" rubies of Burma to the bright reds of Mozambique, ruby has been a symbol of passion, power, and protection for thousands of years.

At Diamond Imports, Daniel personally sources rubies of exceptional colour and quality — for engagement rings, dress rings, earrings, and bespoke commissions across Sydney and Australia-wide.

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What Is a Ruby?

Ruby is the gem-quality red variety of the mineral corundum — the same mineral that produces sapphire. The simple distinction: red corundum is ruby; corundum of any other colour is sapphire. Ruby's vivid red comes from trace amounts of chromium within the crystal structure — the more chromium, the more saturated the red.

Ruby ranks 9 on the Mohs hardness scale, making it the second-hardest natural gemstone after diamond — equal to sapphire. This exceptional durability makes ruby an excellent choice for engagement rings and everyday jewellery, capable of withstanding a lifetime of wear.

Among coloured gemstones, fine ruby is among the rarest and most valuable. Top-quality rubies above 3 carats can rival or exceed equivalent diamonds in price per carat — and the very finest stones from Burma have sold at auction for hundreds of thousands of dollars per carat.

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The Colour of Ruby

Ruby's value is determined more by colour than any other factor. The most prized rubies display a pure, vivid red with no brownish or orange undertone — and ideally with a slight blue tint that gives the stone a deep, glowing intensity. The most desirable tone is medium to medium-dark with high saturation.

"Pigeon's Blood" — The Ultimate Ruby Colour

The most coveted ruby colour in the world is known as "pigeon's blood" — a term used in the trade for centuries to describe a particular saturated, slightly bluish red said to resemble the first two drops of blood from a freshly killed pigeon. The phrase originated in Burma (Myanmar), historically the source of the world's finest rubies. Today, leading gemmological laboratories such as SSEF, Gübelin, and GRS issue formal "pigeon's blood" colour designations for rubies meeting strict colour criteria — a designation that can multiply a stone's value.

Other Colour Variations

While vivid red is most prized, fine rubies also appear in:

• Cherry red — a bright, slightly lighter red, often associated with Mozambican stones
• Crimson — deep, slightly purple-red, found in some Burmese and Vietnamese material
• Raspberry red — a pinkish-red, common in Thai and some Madagascan rubies

The boundary between ruby and pink sapphire is set by colour saturation — there is no universally agreed line, and a gemmologist's judgement is the final word.

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Famous Origins of Ruby

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How Rubies Are Graded

Colour

By far the most important factor. The finest rubies display a pure, vivid, slightly bluish red with high saturation and medium-to-medium-dark tone. Stones that are too dark appear blackish; stones too light fall toward pink sapphire territory. The presence of any brown or orange undertone reduces value significantly.

Clarity

Natural rubies almost always contain visible inclusions — in fact, completely eye-clean fine rubies are so rare that they are sometimes viewed with suspicion (they may be synthetic). Most fine rubies contain characteristic "silk" — fine rutile needles that can actually enhance colour by scattering light through the stone. The questions to ask are: are the inclusions visible from the face-up position, and do they affect the stone's transparency and brilliance?

Cut

Ruby is most commonly cut in oval, cushion, and round shapes — cuts that maximise the appearance of colour and minimise loss of rough. A well-cut ruby shows even colour distribution and good brilliance across its full face-up appearance.

Carat

Fine-quality rubies above 1 carat are significantly rarer than fine sapphires of equivalent size. Fine rubies above 3 carats are exceptionally rare and command per-carat premiums that increase dramatically with size. A 5-carat top-quality Burmese ruby is one of the rarest things in fine jewellery.

Origin

For significant rubies, geographic origin matters enormously. A Burmese origin certificate from a respected laboratory (SSEF, Gübelin, GRS) can add substantial value to a stone — particularly when paired with a "pigeon's blood" colour designation.

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Ruby Treatments — What to Know

Most rubies on the international market have been treated in some way to improve colour and clarity. Understanding the treatment landscape is essential to buying a ruby well — and at Diamond Imports we disclose every treatment in full.

Heat Treatment — Standard and Widely Accepted

The vast majority of rubies in the trade have been heat-treated. Conventional heat treatment uses high temperatures (1,400–1,800°C) to improve colour and reduce visible silk-like inclusions. This treatment is:

• Permanent and stable — once heated, the change is irreversible and the stone requires no special care
• Widely accepted in the trade and disclosed routinely
• Detectable by trained gemmologists, particularly through internal evidence such as altered inclusions

Unheated Rubies — The Premium Category

Untreated rubies of fine natural colour — particularly from Burma or Mozambique — are significantly rarer and command substantial premiums. Top untreated stones are always sold with independent laboratory certification confirming no thermal enhancement.

Fracture Filling — Buyer Beware

Some heavily included low-grade rubies are filled with lead glass to improve apparent clarity. While these "composite" or "glass-filled" rubies look impressive at first glance, they are fundamentally different from natural or simply heat-treated rubies:

• The treatment is unstable and can be damaged by everyday wear, ultrasonic cleaning, or contact with common chemicals (even some jewellery cleaners)
• The stone has a significantly reduced lifespan compared to natural ruby
• Their wholesale value is a small fraction of natural ruby of comparable appearance

This is why a "0.5 carat ruby" at a department store may cost a hundred dollars while a fine natural ruby of the same size costs many thousands. At Diamond Imports we do not sell glass-filled rubies. Every ruby in our collection is natural, with treatments fully disclosed.

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Ruby Engagement Rings

Ruby has been associated with love and passion for centuries — making it one of the most romantically meaningful choices for an engagement ring. At 9 on the Mohs hardness scale, ruby is also exceptionally durable, ideal for daily wear.

Practical considerations when choosing a ruby engagement ring:

• Size matters more than with diamond — fine large rubies are genuinely rare. Many ruby engagement rings feature stones in the 0.75–1.5 carat range, often in halo or three-stone settings that visually amplify the centre stone.
• Halo settings are particularly flattering for ruby, with surrounding diamonds emphasising the warmth of the red colour.
• Yellow gold classically complements ruby's red, while white gold and platinum create cooler, more contemporary contrast.
• Avoid composite rubies for any ring intended for daily wear. Stick to natural heated or unheated stones.

Daniel will guide you through every option — selecting the right ruby for your design, budget, and intended setting, with full transparency on origin and treatment.

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Caring for Your Ruby

Natural and heat-treated rubies are extremely durable and easy to care for. Composite (glass-filled) rubies require entirely different — and far more restrictive — care, which is one of many reasons we do not stock them.

• Warm soapy water with a soft brush is perfect for routine cleaning at home.
• Ultrasonic and steam cleaning are generally safe for natural and heat-treated rubies, but should always be avoided for composite stones.
• Avoid sharp impacts — ruby is hard but not unbreakable.
• Store separately from softer gemstones to prevent scratching them. Ruby will easily damage opal, pearl, and emerald.
• Annual professional check — have the setting inspected once a year to ensure prongs and claws remain secure.

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Ruby Symbolism and History

Ruby is the July birthstone and the traditional gift for the 15th and 40th wedding anniversaries. Across cultures and centuries it has been associated with passion, courage, vitality, and protection. In medieval Europe rubies were believed to protect warriors in battle; in Burma they were embedded into the flesh of soldiers for the same reason. The word "ruby" comes from the Latin ruber, meaning red.

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