Alexandrite Gemstones

What makes alexandrite different from other gemstones?

Alexandrite is a colour-change variety of chrysoberyl, valued above all other chrysoberyls because its chromium content causes its hue to shift dramatically depending on the light source — green to teal in daylight, red to purple-red under incandescent light. This optical effect is caused by the stone's unusually positioned absorption spectrum, which sits almost exactly between the wavelengths of daylight and artificial light. Fine alexandrite is one of the rarest gem minerals on earth; the original deposits near Malysheva in the Ural Mountains of Russia, discovered in the 1830s and reputedly named in honour of Tsar Alexander II, are largely exhausted. Today the primary sources are Brazil, Sri Lanka, Tanzania, and India, each producing material with slightly different colour-change character. Russian alexandrite — where the shift from vivid green to deep red is most pronounced — commands the highest premiums on the market. The strength and completeness of the colour change is the single most important quality criterion when selecting alexandrite.

How to choose a quality alexandrite: what the grading factors mean

When assessing alexandrite, the strength and completeness of the colour change is assessed first — a stone rated as showing a 100% change (full green to full red) is exponentially rarer than one with a 50% or partial shift. Beyond colour change, the base colours in each lighting condition matter: the most valued alexandrite displays a pure bluish-green in daylight (not yellowish-green) and a strong raspberry-red or purplish-red under incandescent light. Clarity in alexandrite follows the Type II classification, meaning eye-visible inclusions are relatively common and accepted, though heavily included stones lose desirability. Cut is important for maximising the colour-change display; ovals, cushions, and rounds are most frequently used because they allow light to interact with the crystal from multiple directions. Carat weight has an outsized effect on price — fine alexandrite above 1ct is genuinely uncommon, and stones above 2ct with strong colour change are rare enough to be considered collector material. Our alexandrites are certified where grading reports are available, with certificates of authenticity provided for all stones.

What does alexandrite cost in the UK?

Alexandrite is one of the most expensive coloured gemstones per carat, reflecting its geological rarity. Price is driven by four factors: the completeness of the colour change, the quality of the base colours in both lighting conditions, the origin of the stone, and the carat weight. Fine Brazilian or Russian alexandrite with a strong, vivid colour change commands significantly more per carat than material with a weak or partial shift. Lab-grown alexandrite is also available and displays the same chemical composition and colour-change phenomenon as natural alexandrite, at a considerably lower per-carat cost, making the optical effect accessible across a wider range of budgets. For context, Bridebook's 2026 UK average engagement ring spend is £2,247 — a natural alexandrite of fine quality as a centre stone would typically sit above this level, while a lab-grown alexandrite in the same carat weight would fall well within it. Both natural and lab-grown alexandrites in our inventory are certified to the same standards.

Is alexandrite durable enough for everyday wear?

Alexandrite registers 8.5 on the Mohs scale of hardness, placing it above sapphire in some references and slightly below it in others — in practical terms, it is one of the hardest and most wear-resistant coloured gemstones available, and it is entirely suitable for daily wear including in ring settings. Its hardness means it resists scratching from most everyday contact. Alexandrite also has no cleavage planes, which distinguishes it favourably from stones such as topaz or tanzanite and means it is less susceptible to chipping under impact. Standard care applies: ultrasonic and steam cleaning are generally safe for alexandrite without fracture-filling or surface coatings, though a soft brush with warm soapy water is always the most conservative approach. When set into one of our rings, alexandrite is well-suited to most setting styles, including bezel settings that offer additional physical protection around the girdle.

Buying alexandrite loose or set into a ring

Alexandrite is available loose or set into one of our rings through a process that moves from consultation to CAD design, then a silver or wax sample for review at our Hatton Garden workshop, before the piece is cast, set, finished, and hallmarked at the London Assay Office. Lead time for a ring set with an alexandrite centre stone is 7 to 14 working days from order confirmation, depending on setting complexity. Loose alexandrite purchases carry a 30-day return policy with no questions asked and no exclusions, and all orders are sent with complimentary insured UK delivery. The colour-change nature of alexandrite makes it worth reviewing in both natural and artificial light before purchase — our Hatton Garden appointments are arranged precisely for this kind of assessment.