Alexandrite: A Buyer's Guide
Alexandrite is the only major gemstone whose entire value rests on something you cannot photograph — it must be seen changing colour, in two different lights, before you can judge it at all.
What alexandrite actually is
Alexandrite is the colour-change variety of chrysoberyl, coloured by trace chromium. Green to blue-green in daylight or fluorescent light; red, raspberry or purple under incandescent light and candlelight.
The mechanism is genuine and unusual. Chromium in chrysoberyl absorbs light in the yellow band, leaving two transmission windows — one green, one red. Daylight is rich in the blue-green end of the spectrum and the stone reads green. Incandescent light is rich in red and the stone reads red. The stone is not changing; the light is, and the stone is unusually sensitive to it.
It was discovered in Russia's Ural Mountains in the 1830s and named for Tsar Alexander II. The green-and-red combination happened to be the colours of imperial Russia, which is a large part of why the stone acquired the status it did.
Colour change is everything
Alexandrite is graded on the strength and completeness of its shift, and nothing else comes close in importance.
| Change strength | What you see |
|---|---|
| Strong (90–100%) | Clean green in daylight to clean red or raspberry indoors. Rare. |
| Moderate (50–80%) | Green-grey to purplish red. The commercial norm. |
| Weak (below 50%) | Grey-green to brownish purple. Often sold at strong-change descriptions. |
You cannot assess alexandrite from a photograph. Two images taken under different lights prove nothing — any stone with a slight secondary hue can be made to look like it shifts by choosing the lighting carefully. Insist on continuous video where the light source visibly moves from one to the other in a single unbroken take, or see it in person. We film every alexandrite this way as standard and would be suspicious of any dealer who does not.
Origin
Russia (Urals)
The historical source, effectively exhausted by the early twentieth century. Russian material is famous for a clean, complete change and is essentially a collector and auction market now. Any Russian alexandrite offered readily should be treated with scepticism unless it carries origin certification from a major laboratory.
Brazil (Minas Gerais)
A significant find at Hematita in 1987 produced material with strong change, some of it comparable to Russian. This deposit is largely worked out, but Brazilian alexandrite remains the benchmark for modern material.
Sri Lanka
Produces the largest stones. The change tends to be less complete — often green to brownish red rather than clean red — but Ceylon is where you look if you need size.
Tanzania and Madagascar
Newer supply. Quality varies widely; some material shows respectable change, much does not.
India (Andhra Pradesh)
Small deposits producing mostly cabochon-grade material, including some cat's-eye alexandrite.
What gets sold as alexandrite but is not
This is the most heavily imitated stone we handle. Certification is not a formality here; it is the entire basis of the transaction.
- Synthetic alexandrite — laboratory-grown chrysoberyl. Chemically identical, often with a stronger change than most natural material, and legitimate when disclosed. Frequently is not.
- Colour-change garnet — natural, attractive, a genuinely interesting stone in its own right, and routinely sold as alexandrite. Usually shifts blue-green to purple-red.
- Colour-change sapphire — also natural and also routinely mislabelled. Typically blue to purple.
- Synthetic colour-change corundum — the oldest imitation, sold as alexandrite since the early 1900s. Shifts grey-blue to amethyst purple, nothing like the real thing, and still fools people.
A report from GRS, GIA, Gübelin or SSEF confirming natural chrysoberyl with colour change is the minimum. For anything above 1ct we would want origin on the report as well.
Other quality factors
Clarity
Eye-clean is expected in faceted material. Alexandrite forms relatively cleanly, so visible inclusions matter.
Cut
Cutters must orient for the strongest change, which is not always the orientation that retains the most weight. A well-oriented 1ct can outperform a poorly oriented 2ct entirely.
Size
Most natural alexandrite is under 1ct. Above 2ct with strong change is genuinely rare, and individual stones above 5ct tend to be known within the trade.
Cat's eye alexandrite
Chrysoberyl produces the sharpest chatoyancy of any gemstone, and cat's-eye alexandrite combines that with colour change. It is one of the rarest things in the gem world.
Durability and setting
Mohs 8.5 with no cleavage and excellent toughness. Alexandrite is entirely suitable for daily wear including engagement rings.
Setting design should let both colours read. Avoid heavy bezels that block light from the sides, and avoid dense diamond haloes that flood the stone with reflected white light and mute the change. A simple solitaire in white metal is the most honest presentation; yellow gold warms the daylight green in a way some buyers dislike.
How we source alexandrite
Sourced to order. Tell us the carat range and the change strength you are after, and be realistic about the relationship between the two — strong change and large size rarely arrive together.
We source through Bangkok, Sri Lankan and Brazilian dealers. Every candidate is filmed as continuous video moving between daylight and incandescent light so you see the actual shift, not two flattering stills. Every stone comes with a laboratory report confirming natural chrysoberyl.
Turnaround is typically two to four weeks. For strong-change material above 2ct, longer, and we will say so rather than offer you a weak-change stone described optimistically.
Frequently asked questions
How can I verify the colour change is genuine before buying?
Insist on continuous video where the light source visibly moves from daylight to incandescent in a single unbroken take. Two separate photographs prove nothing — any stone with a slight secondary hue can be made to look like it shifts by choosing the lighting. We film every alexandrite this way as standard, and you should be suspicious of any dealer who will not.
What is the difference between alexandrite and colour-change garnet?
They are different minerals. Alexandrite is chrysoberyl at Mohs 8.5; colour-change garnet is garnet at Mohs 7–7.5. Garnet typically shifts blue-green to purple-red and is a genuinely attractive stone in its own right, but it is routinely sold as alexandrite at alexandrite descriptions. Only a laboratory report separates them reliably.
Is synthetic alexandrite acceptable?
It is chemically identical to natural chrysoberyl and often shows a stronger, cleaner change than most natural material. As a jewellery choice it is entirely legitimate — provided it is sold as synthetic. The problem in this market is not synthetics existing, it is synthetics being sold as natural. We disclose which one you are buying, always.
Can alexandrite be worn as an engagement ring?
Yes. Mohs 8.5 with no cleavage and excellent toughness makes it entirely suitable for daily wear. Choose a setting that lets light into the stone from the sides — heavy bezels and dense diamond haloes mute the colour change, which defeats the point of owning one.
Why is Russian alexandrite so sought after?
The Ural deposit produced material with an unusually clean and complete change, and it was exhausted by the early twentieth century. Genuine Russian alexandrite is a collector and auction market. Anything offered readily as Russian without origin certification from a major laboratory should be treated sceptically.
What size alexandrite is realistic?
Most natural alexandrite is under 1ct. Above 2ct with strong change is genuinely rare, and stones above 5ct tend to be individually known within the trade. If you want size, Sri Lankan material goes larger but with a less complete change — that is the trade-off, and we will lay it out rather than pretend it does not exist.
Does alexandrite need any special care?
No. It is hard, tough and untreated as a rule, so ordinary care is sufficient. Warm soapy water and a soft brush. It tolerates ultrasonic cleaning better than most coloured stones, though we would still avoid it if the stone has visible inclusions.
Do you ship alexandrite internationally?
Yes, worldwide, with insured tracked courier and full customs documentation. Because colour change is the whole point with this stone, we do live video calls so you can watch it shift in real time before committing, and we schedule those to suit your time zone.
Enquire About an Alexandrite
Tell us the carat range and the change strength you want. We will source certified natural material and film each candidate moving between daylight and incandescent light so you see the real shift.
Tinch Jewels · Borivali West, Mumbai 400092, India · Worldwide insured shipping
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