Discovering Rubies: How to Identify in jewellery

Ruby, a member of the family of precious stones, has a way of stealing the spotlight. That glowing red, alive under every flicker of light, has inspired poets, collectors and lovers for centuries. In ancient texts, including the Bible, ruby sits at the top of the gemstone pecking order, tied to love, passion and courage. Today, it’s still the colour many people think of when they picture a love token.

jewellery plays a crucial role in the presentation and setting of rubies, enhancing their natural beauty and allure. From elegant necklaces to exquisite rings, the choice of jewellery design can greatly influence how the ruby is showcased. Many jewelers consider factors such as metal type, cut, and style to best complement the gemstone's rich hues. A well-crafted piece of jewellery not only displays the ruby to its fullest advantage but also protects the stone from potential damage.

If you’re trying to work out whether a ruby in a piece of jewellery is the real thing, the good news is you don’t need to be a scientist for proper identification and to make a sensible call. A few smart checks, a basic understanding of treatments and imitations, and knowing when to lean on a gem lab will take you a long way.

Regular ruby inspection is crucial for anyone dealing with these captivating gemstones. Through routine checks, collectors and jewelers can ensure the authenticity and quality of rubies, identifying any potential treatments or enhancements. Inspections, whether at home or through expert evaluation, offer peace of mind and help maintain the integrity of your gemstone investment.

What gives ruby its unmistakable red

Ruby is the red variety of corundum, the same mineral family as sapphire. A tiny amount of chromium replaces aluminium in the crystal structure, and that’s what creates the vivid red. Under certain lights, ruby can almost glow from within. That’s not your eyes playing tricks. Chromium makes many rubies fluoresce under ultraviolet light, which boosts the perceived richness in daylight.

A few quick colour clues:

● The best reds feel saturated and intense without looking black in dim light.

● Some rubies show a touch of pink, purple or orange. The sweet spot for many collectors is a rich, slightly bluish red often called pigeon’s blood. It’s a trade term, not a scientific grade, and proper use usually relies on an independent lab report.

● Ruby shows pleochroism, meaning it can show slightly different shades when viewed from different directions. With a simple dichroscope, you’ll see red to purplish red pairs.

Simple checks you can do before you buy

You won’t confirm every detail at home, but you can rule out a lot of pretenders with common sense and a loupe.

● Ask for the paperwork

○ Trusted jewellers provide reports from labs like GIA, AGL, GRS, SSEF or a respected local gemmologist. Look for treatment disclosure. Heat treatment is common and generally accepted when disclosed. Surface-reaching fracture filling with lead-glass is a different category and affects value and care.

● Look at the stone in different lights

○ Daylight, office LED, warm lamplight. A quality ruby holds its colour without going brown or dull. If it looks amazing only under one showroom light, be cautious.

● Inspect the facet junctions

○ Ruby is hard, rating 9 on the Mohs scale. Old glass imitations and low-quality composites show rounded, abraded facet edges after short wear.

● Use a 10x loupe if you can

○ Natural rubies often have fine rutile needles known as silk, tiny mineral crystals, or fingerprint-like patterns. A perfectly glassy, flawless interior can be a sign of synthetic corundum or heavy fracture filling. High-end natural rubies can be very clean, but totally inclusion-free is unusual.

● Watch for telltale flashes

○ Blue or purple flashes dancing along cracks are a red flag for lead-glass filling. You might also see gas bubbles in the filled fissures.

● Feel the weight

○ Glass feels lighter than expected for its size. Ruby has a higher density than glass.

Never do a scratch test. You’ll likely damage the setting or the stone, and it proves very little in a modern trade filled with advanced simulants.

Natural, treated, or lab-grown

Ruby can be natural or grown in a lab. Natural stones can be untreated or treated. These categories have different values and care notes.

● Natural untreated

○ Scarcer and priced accordingly, especially when the colour is strong and the stone is clean. Many show fine silk or other small inclusions on magnification.

● Natural heat-treated

○ The most common. Heating can dissolve rutile silk and improve colour and clarity. This is widely accepted when disclosed.

● Flux-healed or diffusion-treated

○ Flux healing uses molten flux during heating to heal cracks; diffusion adds colouring agents near the surface. Diffusion can create colour concentrated near facet edges or a coloured rim. These need clear disclosure.

● Lead-glass filled composite

○ Very inexpensive. Glass fills surface-reaching fissures, making a previously non-gemmy piece look transparent and bright. These are fragile to heat, chemicals and ultrasonic cleaning.

● Lab-grown corundum

○ Chemically and physically the same mineral as natural ruby, but grown in a factory. Flame-fusion material shows curved growth lines and may have gas bubbles. Flux-grown can look very clean, with wispy flux residues or fingerprints that differ from natural patterns. Lab-grown ruby is lovely in its own right, but should be priced and described accordingly.

What a microscope reveals

If you have access to a jeweller’s microscope or a decent loupe, a ruby inspection can reveal that the internal world of ruby is fascinating and informative.

Typical natural features:

● Rutile silk: fine needle-like inclusions, sometimes forming intersecting patterns. Partial melting of silk is a sign of heat treatment.

● Crystal inclusions: small crystals of other minerals with sharp edges; sometimes with tiny stress halos.

● Fingerprints: healed fluid inclusions that look like tiny branching patterns.

● Growth zoning: angular or hexagonal colour bands inside the crystal.

Clues for synthetics and heavy treatments:

● Curved striae: sweep-like curved lines in flame-fusion lab ruby.

● Gas bubbles: round bubbles, especially in glass-filled fissures.

● Flux residues: wispy or reflective flakes in flux-grown material.

● Colour concentrations at facet edges or a coloured “rim”: possible diffusion.

Ruby and its red lookalikes at a glance

Material	Key visual clues	Refractive index (RI)	UV reaction	Common inclusions	Notes
Natural ruby	Strong, rich red; pleochroism; sharp facet edges	1.76 to 1.77 (double)	Often strong red under LW UV	Rutile silk, fingerprints, angular growth zoning	Hardness 9; usually some inclusions
Heat-treated ruby	Similar to natural; silk may be dissolved	1.76 to 1.77 (double)	Often strong red	Partially melted silk, healed features	Widely accepted when disclosed
Lead-glass filled ruby	Very bright, mirror-like flashes; fissures with glass	1.76 to 1.77, but composite behaviour	Sometimes dull or uneven	Bubbles in fissures; blue flashes	Poor resistance to heat and chemicals
Lab-grown ruby (flame-fusion)	Very clean; curved growth lines	1.76 to 1.77 (double)	Often strong red	Curved striae, gas bubbles	Cheaper; should be clearly labelled
Red spinel	Bright red; singly refractive; no pleochroism	1.718 (single)	Often strong red	Octahedral crystals, no doubling	Often mistaken historically for ruby
Red garnet (pyrope/almandine)	Deeper, sometimes brownish red; no pleochroism	1.73 to 1.77 (single)	Usually inert	Rounded crystals, “treacle” patterns	Heavier feel; different sparkle
Red glass	Flat colour; soft facet edges when worn	1.50 to 1.70 (single)	Usually inert	Gas bubbles, swirl lines	Very low cost

A handheld refractometer and dichroscope make quick work of separating many of these.

Easy tools that make you look like a pro

● Dichroscope

○ Ruby shows two shades of red due to double refraction. Spinel and garnet don’t.

● UV torch

○ Many rubies glow bright red under longwave UV. Iron-rich stones can be weak. Spinel might glow but often a slightly different character. Glass is usually dull.

● Spectroscope

○ Ruby shows chrome absorption bands, including a sharp line around 694 nm and pairs around the blue-green region. It sounds geeky, but once you’ve seen the pattern you won’t forget it.

● Refractometer

○ Confirms RI and double refraction. Ruby sits at about 1.76 to 1.77 with birefringence around 0.008. Spinel is singly refractive at about 1.718.

● Chelsea filter

○ Many ruby and red spinel look red through the filter, but ruby with strong chrome can appear bright red. It’s a support test, not a verdict.

Colour labels decoded

Gem dealers love colour names. Here’s what they usually mean in practice.

● Pigeon’s blood

○ A vivid, slightly bluish red that still looks red in low light and often shows strong fluorescence. Labs that use the term apply strict criteria. Always tie this claim to a lab report.

● Vivid red, vivid saturation

○ Saturation is about how pure the colour looks. High saturation with good tone is what creates that famous glow.

● Pink sapphire vs ruby

○ Both are corundum. Where pink ends and red begins depends on the lab and the country. In Australia you’ll see both terms used. A report settles it if that distinction matters to you.

Origin plays into the story as well. Burmese (Myanmar) stones with strong fluorescence have a long history and can carry a premium. Mozambique, Madagascar, Sri Lanka and Thailand also produce beautiful rubies, often with their own character. Origin should be supported by a reputable lab because visual guesses can mislead.

Price clues that actually help

● Size matters

○ Prices jump at weights above 1 carat, and again above 2 and 5 carats for top stones.

● Treatment disclosure

○ Untreated stones with top colour cost more. Heat-treated stones are more common and priced lower for equivalent look. Lead-glass filled pieces are far cheaper.

● Clarity and cut

○ A well-cut ruby that faces up bright will outshine a windowed stone of the same weight. Minor inclusions are normal. A totally clean look at a bargain price might not be what it seems.

● Paperwork

○ A lab report is worth real money at the point of purchase and later for resale or insurance.

● Deal too good to be true

○ A stone advertised as “untreated pigeon’s blood” at a giveaway price needs careful verification.

Care and cleaning tips

Ruby is tough, but its treatment status matters for maintenance.

● Safe methods

○ Warm water, mild detergent and a soft brush work for most rubies. Rinse well.

● Ultrasonic and steam cleaners

○ Usually fine for untreated and standard heat-treated stones in sturdy settings. Avoid if you see any fractures or if you don’t know the treatment.

● Never heat or acid clean a lead-glass filled ruby

○ Glass can soften or etch, leaving a frosty look and visible pits.

● Check settings regularly

○ Claw-set ovals are classic. Have a jeweller check prongs, especially on rings that see daily wear.

A short gem-history snack

Ruby’s status as the gemstone of love isn’t a new marketing line. Ancient texts often ranked it as the most precious of the precious. Kings and queens wore ruby to signal power and passion. Warriors believed it could protect them. Today, many people still choose ruby to mark milestones of affection, strength and loyalty.

See the difference in person

Studying real pieces against the points above teaches your eyes faster than any article can. If you’re near Melbourne, you can handle a range of rubies in comfortable spaces and ask every question on your mind.

● The Glen Shopping Centre showroom

○ 235 Springvale Rd, Glen Waverley VIC 3150

○ High jewellery, bridal pieces and birthstone collections on display. Two private rooms are available to chat with jewellery specialists, sketch ideas and compare stones. Free engraving is offered, and custom made options are available.

● Melbourne CBD showroom

○ 413/220 Collins St, Melbourne VIC 3000

○ A curated selection of fine pieces in a central location. Visits are by appointment so you can take your time and get personal guidance.

PurpleMay crafts in solid gold with natural gemstones and certified diamonds. The team has operated in Melbourne since 1998, with a strong record across design, fabrication and stone setting. If you’re weighing up a ruby, you can request a lab report, review treatment disclosure and examine the stone under magnification on site.

A recent highlight that’s perfect for hands-on learning: a pair of oval untreated rubies totalling 4.06 carats in a vivid red, paired with pear-shaped diamonds totalling 3.62 carats. The rubies show lively colour and an impressive crystal look, set in classic claws beside elegant diamonds. It’s a great example of how rubies and diamonds can amplify each other’s fire.

Quick FAQ for first-time ruby buyers

● How do I know it’s real?

○ Ask for an independent lab report. Check for disclosure of any treatment. Inspect the stone under magnification and look for natural internal features.

● Are all treatments bad?

○ No. Traditional heat treatment is common and accepted when disclosed. Lead-glass filling drastically lowers durability and value, so it should be priced accordingly and handled with care.

● Is lab-grown ruby fake?

○ It’s real corundum grown in a factory. It should be sold clearly as lab-grown and is priced lower than natural.

● What’s the difference between ruby and pink sapphire?

○ Both are corundum. The label depends on colour strength. Different labs draw the line in slightly different places.

● Can I clean my ruby with household cleaners?

○ Stick to mild detergent and warm water. Avoid strong chemicals, especially if the stone has fractures or unknown treatment.

A checklist you can screenshot

● Independent lab report for the centre stone

● Clear disclosure of any treatment

● Notes on origin if claimed, supported by a lab

● Visual check in multiple lights

● Loupe inspection of inclusions and facet edges

● Setting quality and comfort on the finger or ear

● Care instructions tailored to the treatment type

● Return policy and insurance valuation in writing

When to involve a lab or a professional

● You’re paying a premium for “untreated” or for a named origin like Myanmar

● The stone looks very clean and very bright at a low price

● The colour seems concentrated at facet edges or the exterior

● You suspect glass filling due to blue flashes or bubbles

● You want a piece that will be worn daily and need care guidance

An hour with a qualified gemmologist, plus a formal report for significant purchases, removes doubt. It can also help you compare two similar-looking rubies and decide which is best for your taste and budget.

Why internal features are your best friend

It’s tempting to hope for a totally flawless interior, but those tiny silk needles or a gentle fingerprint can be comforting signs of nature. They give personality to the stone and often help it hold light in a pleasing way. Clean stones exist, yet a natural ruby that looks like coloured glass under the loupe is uncommon.

Picking the right setting for ruby

● Claw settings

○ Show off the colour and let light in. Make sure claws are secure, especially at the corners of cushions or ovals.

● Halo or three-stone designs

○ Diamonds or white sapphires around a ruby increase contrast and make the red pop. Pear-shaped side diamonds beside an oval ruby are a classic, elegant pairing.

● Metal colour

○ Yellow or rose gold warms the red. White gold or platinum gives crisp contrast. There’s no wrong answer; it’s about the mood you prefer.

Final tip from the bench

Trust your eyes first, then verify with evidence. If the colour makes your heart skip and the stone still charms you after you’ve checked it under different lights and under a loupe, you’re on the right track. Back your instincts with the right paperwork, and you’ll enjoy that red glow for decades.
 If you’d like a guided look at ruby options, or to turn a story or milestone into a custom-made piece, you can drop in at The Glen or book an appointment in the CBD. Bring any ideas you have, from sketches to screenshots. The team can talk through design, stone choices, treatment disclosure and long-term care so your piece stays radiant for the life moments you have in mind.

 

Where love meets craftsmanship 

At PurpleMay, every ruby carries more than light — it holds a heartbeat, a memory, and a promise. Each piece is a quiet declaration of strength and tenderness, crafted to honour the woman who wears it. Whether it marks a new beginning, a hard-won victory, or simply the joy of being seen, your jewellery becomes part of your story — a reflection of who you are and what you choose to love.

Visit our Melbourne showrooms or connect with our jewellers to begin your bespoke journey. Together, we’ll design a creation that speaks your truth — timeless, powerful, and uniquely yours.