Ruby

Red colour, strength and personal meaning

Ruby is associated with red, but that colour contains a whole world of variation: pinkish red, red with a purplish hue, light and delicate shades, and stones with deep colour and a strong presence.

Each stone has its own character, shaped by the interplay of colour, inclusions, cut and the way it responds to light.

Ruby combines beauty with high hardness, making it a possible choice for jewellery worn every day. Alongside its gemological properties, it has been associated throughout history with love, passion, courage and strength.

Ruby at a gemological glance

Property	Information
Mineral	Corundum
Chemical composition	Aluminium oxide — Al₂O₃
Main cause of colour	Traces of chromium within the crystal
Colour	Red, sometimes with pink, purple or orange hues
Hardness	9 on the Mohs scale
Refractive index	Approximately 1.762–1.770
Specific gravity	Approximately 4
Special phenomena	Some stones show a star; many exhibit red fluorescence

Ruby and sapphire belong to the same mineral: corundum. Red corundum classified as ruby has its own name; the other colours belong to the world of sapphire.

The boundary between light ruby and pink sapphire is not always clear, and laboratories and markets may classify stones close to that boundary differently.

Where does the red colour come from?

Pure corundum is colourless. In ruby, traces of chromium replace some of the aluminium in the crystal and change the way the stone absorbs light.

Chromium causes the stone to absorb certain wavelengths, while red light reaches the eye, producing the colour we see.

In many rubies, chromium also produces red fluorescence: under suitable lighting, the stone emits additional red light that can give it a lively glow. Iron can weaken this effect.

Two stones of a similar hue may therefore look very different in daylight and artificial lighting.

What affects quality and price?

Two rubies of the same weight can differ greatly in quality and price. For fine, rare stones, the differences can reach thousands of dollars per carat or more.

Colour is a central factor. Hue, saturation, brightness and evenness affect a stone's appearance and value. A darker stone is not necessarily better: its colour should remain lively and respond beautifully to light.

The term Pigeon Blood describes a particularly sought-after, vivid red colour in ruby. Fine stones meeting the criteria for this designation are among the most expensive, but definitions vary between laboratories and the designation alone does not determine price.

Clarity refers to inclusions and internal features. Inclusions are common in natural ruby, and not every inclusion detracts from its beauty. Some contribute to a soft appearance; others may affect transparency or durability.

Cut affects how light travels through the stone and returns to the eye. A successful cut considers colour, crystal structure and optical properties. It can highlight the colour and bring the stone to life; a less successful cut may create dark areas or a transparent area in the centre, known as a window.

Weight also affects price. Gemstone weight is measured in carats; one carat equals 0.2 grams. Large, high-quality rubies are rarer, so their price per carat may rise with size.

The stone's treatments and origin can also have a significant effect on value.

Does geographic origin matter?

Rubies come from Myanmar, Mozambique, Madagascar, Tanzania and Vietnam, among other sources.

Myanmar ruby has a special historical standing in the market, and Mozambique is an important source of ruby today.

Origin may add to the value of a fine stone, but a country's name does not guarantee quality. Every source produces stones of different qualities, so we first examine the stone itself: colour, clarity, cut, treatments and response to light.

A natural ruby can also be treated

Natural describes a stone formed in nature. It can be natural and still undergo treatment to improve its appearance.

Standard heat treatment is a common, accepted treatment for ruby, intended to improve colour and the appearance of inclusions. It differs from glass filling, usually with lead glass, which is common in fractured, lower-quality material. Filling can greatly improve transparency and appearance, but significantly affects value and durability. It is important to know about it before purchase or jewellery work.

A beautiful appearance alone does not tell us what we are looking at. Before choosing or setting a stone, it is important to learn as much as possible about its treatment history.

A fine ruby showing no indications of heating may be rarer and more expensive than a similar heated stone. However, the absence of heating does not by itself make a stone high quality: colour, clarity and cut still matter.

Laboratory-grown ruby and imitations

Rubies are also grown in laboratories. They belong to the same mineral and have a similar chemical composition and basic properties to natural ruby, but their origin is different.

There are also imitations and other materials that resemble ruby but are not ruby.

The distinction matters both for price and for the expectations of the person choosing the stone. When buying ruby, it is important to know whether it is natural, laboratory-grown or another material.

A gemological laboratory report can help identify the stone, establish natural or laboratory-grown origin and detect treatments. In some cases it also includes an opinion on geographic origin.

A star within the stone

Some rubies show a star under a focused light. This effect is caused by light reflecting from tiny inclusions aligned in particular directions within the crystal.

To reveal it, the stone is usually cut as a cabochon: a smooth, rounded surface.

In star ruby, the inclusions are part of the beauty being sought. The quality and position of the star, the colour and the stone's overall appearance all contribute to its character and value.

Is ruby suitable for an everyday ring?

Ruby can suit a ring worn regularly, including an engagement ring. Its high hardness provides good resistance to scratching, but does not make it immune to impacts or fractures.

Before setting it, we examine its condition, treatments, shape and the positions of inclusions and fractures. The setting and the way the jewellery will be worn also matter.

A fracture-filled stone, particularly one filled with lead glass, requires a different approach from a ruby without that treatment.

In custom design, we connect your chosen stone with a structure that presents it beautifully and suits your use.

Sources Around the World

Familiar ruby sources include Myanmar, Mozambique, Madagascar, Tanzania and Vietnam. Origin can be part of the information accompanying a stone, but does not replace assessment of quality and treatments.

Spiritual and Symbolic Meaning — Beliefs and Traditions

In various traditions, ruby symbolises love, passion, courage, vitality and strength. Its red colour has been associated with life, emotion and presence, and it has appeared throughout history in royal and aristocratic jewellery.

Many also associate ruby with fertility, alongside love, passion and vitality.

In gemstone symbolism, ruby is also associated with abundance, confidence and being true to oneself. It can serve as a reminder to act courageously, make room for emotion and connect with what matters to us.

In a couple's jewellery, it can represent deep love and commitment; in a personal piece, inner strength, renewal or a meaningful milestone.

These meanings belong to the realm of belief and symbolism. They can give jewellery personal significance, but they are not proven gemological properties or a promise of healing, protection or a change in health.

Your ruby, in jewellery created for you

Choosing a ruby begins with meeting the stone itself: seeing it in different lighting, getting to know its colour and understanding how it can become part of a piece of jewellery.

At TzurGems Jewelry & Gemstones, we combine Guy's gemological knowledge with the craftsmanship of Rafael, an artisan goldsmith, to create jewellery suited to both the stone and the person who will wear it.