Alexandrite Engagement Rings Australia
By Jared James · Last updated 17 May 2026
Quick answer
Alexandrite is a rare colour-change variety of chrysoberyl that reads green in daylight and red-purple under incandescent light. It is 8.5 on the Mohs scale, harder than emerald and almost as hard as sapphire, so it is well suited to engagement rings. Fine natural stones are among the most expensive gems per carat.
What alexandrite is
Alexandrite is a chrome-bearing variety of chrysoberyl. The chromium absorbs light in a narrow band so the eye picks up either the green or the red wavelengths depending on the light source. Lab-grown alexandrite is the same crystal with the same hardness and the same colour-change effect.
Colour and look
Green to bluish-green in daylight, red to purplish-red under incandescent or candlelight. The finest stones show a strong, complete shift, sometimes described as "emerald by day, ruby by night". Lower-grade stones shift from olive or khaki green to brownish red.
Hardness and durability
Alexandrite is 8.5 on the Mohs scale with excellent toughness. It is one of the hardest coloured gems and stands up well to everyday wear. Fine for engagement rings and daily-wear rings, though the cost of natural stones usually makes them more of an occasion piece.
What to look for
The strength and completeness of the colour change is the main quality factor. Pure vivid green to pure vivid red is the gold standard. Stones that shift dramatically and look saturated in both states command extreme premiums. Clarity, cut and size matter on top.
Treatments and origins
Natural alexandrite is usually untreated. Russian alexandrite from the Ural Mountains, discovered in 1830, is the historical benchmark and now extremely rare. Sri Lanka, Brazil, India, Tanzania and Madagascar are the current sources. Lab-grown alexandrite is widely available and offers the same colour-change effect at a fraction of the price.
Best uses
A statement engagement ring for someone who wants something genuinely rare and visually striking. Drop earrings and pendants showcase the colour change as the wearer moves between light sources. Lab-grown alexandrite makes large, vivid colour-change stones realistic at a much wider price range.
Care
Clean with warm soapy water and a soft brush. Ultrasonic and steam cleaners are generally safe. Alexandrite is durable enough for everyday wear. Store separately from harder gemstones.
Price
Fine natural alexandrite with strong, complete colour change reaches tens of thousands of dollars per carat at the top of the market. Lab-grown alexandrite delivers the same visual effect at a tiny fraction of that price and is the practical choice for most buyers who want the colour-change look.
Designing a custom ring
Start a custom design
Coloured-stone engagement and dress rings are made to order. Tell us what you have in mind and we will help you compare stone options, metal choices and settings.
Start a custom designFrequently asked questions
- Why is alexandrite so expensive?
- Natural alexandrite with strong, complete colour change is genuinely rare. The original Russian deposits were exhausted in the 19th century and new sources rarely match that benchmark. Lab-grown alexandrite offers the same colour change at a much lower price.
- Is lab-grown alexandrite a real alexandrite?
- Yes. It is the same chrysoberyl with the same chromium content and the same colour-change effect, grown under controlled conditions. It tests as alexandrite.
- Will alexandrite always show a colour change?
- Yes, in any natural or lab-grown alexandrite. The strength and completeness of the shift varies between stones. Move the ring between a window and a warm lamp to see how strong the effect is.
- Is alexandrite hard enough for an engagement ring?
- Yes. At 8.5 on the Mohs scale, alexandrite is harder than most coloured stones and very suitable for daily wear.
Still deciding
Talk through alexandrite with us
Send what you have in mind, even if that is only a colour, a budget and a piece of jewellery type, and we will help you compare options.
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