Alexandrite: June's Colour-Changing Birthstone
Alexandrite is one of three June birthstones — pearl and moonstone are the others — and the most rare and valuable of the three. Discovered in the Ural Mountains of Russia in 1834 and named after the future Tsar Alexander II, alexandrite is famous for its dramatic colour change: green in daylight, red under incandescent light. This guide covers what alexandrite is, where it comes from, and what to look for when buying one.
In short: Alexandrite is one of three June birthstones (alongside pearl and moonstone) and the rarest of the trio. A chrysoberyl variety that displays green in daylight and red under incandescent light — a dramatic colour shift caused by trace chromium. Durable at Mohs 8.5. Fine 1-carat alexandrite starts at £3,000-5,000 for Brazilian or African origin; Russian-origin stones command 2-3 times that.
What is alexandrite
Alexandrite is a colour-changing variety of the mineral chrysoberyl (beryllium aluminium oxide), scoring 8.5 on the Mohs hardness scale. The colour change comes from trace amounts of chromium replacing aluminium in the crystal structure — under daylight (or any blue-rich light) the stone appears teal-green to deep emerald; under incandescent light (warm yellow-red) it shifts to raspberry-red or purple. The most prized specimens show a strong, complete colour shift; lower-quality stones display only a partial change.
Origin and supply
Original Russian alexandrite from the Ural Mountains is the historical benchmark — finely-grained, with the cleanest colour change. The Ural mines were largely depleted by the late 19th century. Modern alexandrite comes from Brazil, Sri Lanka, Madagascar, Tanzania, and India. Brazilian alexandrite (notably the 1987 Hematita discovery) produces particularly strong colour change. Sri Lankan stones tend to be larger but often show less dramatic shifts.
Pricing and value
Fine alexandrite is among the most expensive coloured gemstones — prices comparable to ruby and sapphire of equivalent quality. A 1-carat alexandrite with strong colour change starts around £3,000–£5,000 for Brazilian or African origin, with Russian-origin stones commanding 2–3 times that. The price scales steeply with carat weight: a 3-carat fine alexandrite can run £30,000–£60,000. Colour-change quality matters more than size — a small but dramatic stone often costs more than a larger weak-shift one.
Alexandrite in jewellery
Alexandrite's 8.5 hardness makes it durable enough for daily-wear engagement rings, eternity bands, and pendants. The colour change works best in pieces that move between indoor and outdoor lighting — a ring or pendant gets noticed more than earrings (where the stones are typically viewed in one lighting condition). For showcasing the colour shift, a setting that exposes the stone from multiple angles (open prong settings rather than bezel) is most effective.
Frequently Asked Questions
Is alexandrite a real gemstone?
Yes — alexandrite is a natural variety of chrysoberyl that occurs in mining deposits around the world. It is one of the rarest coloured gemstones and was the first gem species discovered to display reliable colour change. Synthetic alexandrite has been produced since the 1960s and is widely used for less expensive jewellery; reputable retailers always disclose whether a stone is natural or synthetic.
How can I see the colour change in alexandrite?
Two lighting conditions reveal it best. Hold the stone in direct daylight (or under a fluorescent or LED daylight bulb) — it should appear green to blue-green. Then move it under a warm incandescent bulb or candlelight — fine alexandrite shifts to red, purple-red, or raspberry. The shift should be obvious and complete; if the colour change is subtle or partial, the stone is lower grade.
Is synthetic alexandrite worth buying?
Lab-grown alexandrite produced via the Czochralski or floating-zone methods is chemically identical to natural alexandrite and displays the same colour change. It costs 70–90% less than natural alexandrite of equivalent quality and is an excellent option for buyers who want the stone's optical character at an accessible price. Most jewellery-grade alexandrite on the market today is synthetic; ask explicitly for documentation of origin.
How does alexandrite compare to other June birthstones?
Pearl is the traditional June birthstone — organic, soft (Mohs 2.5–4), and best suited to occasional wear. Moonstone is the second alternative — soft (Mohs 6) with adularescent sheen. Alexandrite is the rarest and most durable of the three, suited to daily-wear engagement rings. For buyers who want a June birthstone for everyday wear, alexandrite is the practical choice. For a softer, organic look, pearl or moonstone.
How do I care for alexandrite jewellery?
Alexandrite is durable enough for routine ultrasonic and steam cleaning. Clean with warm soapy water and a soft brush for regular care. Annual prong inspection by a jeweller is recommended for ring-set stones. Store separately from softer gemstones to avoid scratching them. With normal care, alexandrite jewellery lasts a lifetime without colour fading or wear.
Explore alexandrite jewellery at Reve
Reve Diamonds creates bespoke alexandrite pendants, earrings, and rings at our London showroom. Browse our engagement rings collection for inspiration or contact us for a custom commission featuring an alexandrite centre stone.
