Education

Rubies

Pigeon's blood, Mogok, Montepuez — and the treatments every ruby buyer must understand.

Red ruby crystal under examination
01

What to look for in a ruby

Ruby is red corundum, coloured by chromium — the same mineral as sapphire, at the same 9 on the Mohs scale. Chromium also makes many rubies fluoresce red in daylight, which adds the inner glow the finest stones are famous for. The market's pinnacle term is pigeon's blood: a vivid, pure red that laboratories grade against strict criteria.
  • Colour — ruby's red depth comes from chromium: more chromium means richer red, often with fluorescence that amplifies intensity
  • Heat status — heat improves clarity and often the colour
  • Treatment status — other treatments include lead glass filled, flux-healed filling or even oil/resin filling
  • Origin — Burmese (Mogok) provenance carries the strongest premium
  • Clarity — inclusions are expected; transparency and brightness matter more
  • Size — fine unheated rubies from Mogok over 5 carats are genuinely rare, and prices rise steeply
What this means when you buy

Every ruby in the catalogue is listed with its laboratory report, heat status, and — where graded — the lab's colour term, quoted exactly.

What does pigeon's blood actually mean?

A colour grade — not an origin. The term began in the Mogok valley of Burma; today laboratories such as Gübelin and SSEF apply defined colour and quality criteria before using it on a report.

Why do rubies glow?

Burmese rubies—low in iron—fluoresce vividly. Mozambique rubies, higher in iron, show weaker fluorescence and a deeper, darker red.

World map of principal coloured gemstone deposits, including the ruby sources Burma (Mogok) and Mozambique (Montepuez)
02

Where rubies come from

Two origins dominate the fine-ruby conversation today: the historic valley of Mogok in Burma, and the Montepuez deposit in Mozambique, discovered in 2009, which now supplies much of the world's fine ruby.
  • Burma (Mogok) — the classic source; strong fluorescence and lack the iron
  • Mozambique (Montepuez) — discovered in 2009; large, transparent crystals, now the major modern supply
  • Thailand and Cambodia — historically important commercial sources
  • Madagascar, Tanzania, Vietnam & Tajikistan — smaller producers of fine material
What this means when you buy

Fine Mozambique rubies have reached fine gem qualities at major laboratories — at prices still below equivalent Burmese stones. For value, that gap is worth understanding.

Is a Burmese ruby always better?

Not always, we need to compare fairly to other stones with similar quality from other origin in order to judge correctly.

Does the report say Burma or Myanmar?

Laboratories vary; many reports still use Burma (Myanmar) by trade convention. Both refer to the same origin.

03

Treatments: the chapter that protects you

Ruby treatments span a wide spectrum, and the words on the report place a stone in entirely different price categories. Heat alone is trade-accepted. Flux-healed stones carry residues in fissures from the heating process. Lead-glass composites — heavily fractured material rebuilt with glass — are a manufactured product that must never be priced as fine ruby.
  • No indication of heating — the premium category
  • Heated — accepted and stable when disclosed; the market norm
  • Heated with residues (flux-healed) — glassy residues in healed fissures; must be disclosed and priced accordingly
  • Lead-glass filled (composite) — fragile and low-value; damaged by household chemicals, heat, even citrus — a different product altogether
  • Oil/resin filled — quite commonly seen in rubies with fissures that can be filled to improve clarity
What this means when you buy

We do not trade lead-glass composite rubies. Every stone we list carries a recognised laboratory report stating heat status and any residues in full.

How fragile is a lead-glass ruby?

They are generally stable under normal wear or storage. They are sold legitimately as low-cost composites — the problem is only when they are priced as natural ruby.

What does 'minor residues' mean on a report?

During heating, flux can heal fissures and leave small glassy traces. Laboratories grade the extent. Minor residues in an otherwise fine heated ruby are accepted by the trade — at the right price.

GRS
Gübelin
SSEF
AGL
GIA
04

Certification: reading a ruby report

For ruby, the report is not a formality — it is the product description. It should state natural origin, heat status, the extent of any residues, an origin opinion, and, where earned, a colour term such as pigeon's blood.
  • SSEF — Swiss Gemmological Institute, Basel; founded 1972
  • Gübelin Gem Lab — Lucerne; founded 1923, the oldest of the Swiss houses
  • GRS — GemResearch Swisslab, Lucerne; founded 1996, widely used in the coloured-stone trade
  • AGL — American Gemological Laboratories, New York; founded 1977
  • GIA — Gemological Institute of America; founded 1931, the most familiar name to consumers
What this means when you buy

A pigeon's-blood term from different laboratories is not interchangeable — criteria differ. We tell you which lab graded it, and what that means for resale.

Do I need two reports for an important ruby?

At the top of the market, yes — a second opinion on origin and colour term is standard practice and strengthens resale.

Avoid ultrasonic cleaners
Avoid steam & sudden heat
Clean with warm water & mild soap
Store separately in a soft sleeve
05

Caring for a ruby

Like sapphire, untreated and simply heated rubies are robust: Mohs 9, no cleavage, suitable for daily wear.
  • Warm water, mild soap, and a soft cloth are always safe
  • Avoid ultrasonic cleaners or steam for gemstones
  • Keep lead-glass composites away from chemicals, heat, and ultrasonic cleaners entirely
  • Protective settings guard girdle edges on rings worn daily
What this means when you buy

If you are unsure what category your ruby is in, bring it to us for evaluation and observation under the microscope settles it.

My ruby went dull after cleaning — why?

There could be many reasons for that, the best would be to bring it to us for full evaluation.

Frequently asked

Ruby questions buyers ask us most often.

Where can I buy fine rubies in Hong Kong?

Gem Solutions Ltd. holds verified rubies with reports in Central, Hong Kong, and sources to brief through our trade network. Every stone is examined on our own bench and listed with its laboratory report.

Why are rubies more expensive than sapphires?

Both can be equally as expensive depending on the size, colour, clarity and cutting. Both in fine quality can fetch a premium price.

Is a lead-glass filled ruby ever worth buying?

As an inexpensive, honest costume purchase, perhaps — they can look attractive. As a gemstone investment, no. They are fragile, low-value manufactured composites, and must be disclosed as such.