Emerald by Day, Ruby by Night

Alexandrite is the colour-change variety of chrysoberyl, famous for appearing a bluish green in daylight and a purplish red under incandescent light — a dramatic shift caused by the way chromium within the crystal absorbs different wavelengths under different light sources. Fine alexandrite showing a strong colour change is among the rarest and most valuable of all coloured gemstones.

Gemologically, alexandrite is described as transparent, with a vitreous luster — qualities that shape how it catches and carries light once cut. Its colour comes from chromium, and a Mohs hardness in this range holds up well to daily wear, making it a practical choice for rings as well as earrings and pendants.

What Causes the Colour Change

Alexandrite's colour change is caused by chromium — the same element responsible for the green of emerald and the red of ruby — substituting into the chrysoberyl crystal structure. Chromium absorbs light unusually strongly in the yellow region of the spectrum while transmitting both blue-green and red light fairly equally. In daylight, which is rich in blue-green wavelengths, the eye perceives the stone as bluish green; under warm incandescent or candlelight, which is rich in red wavelengths, the same stone appears purplish red. (Some other coloured gems get their colour from copper or vanadium rather than chromium — Paraíba-type tourmaline, for example, owes its electric blue-green to copper — but in alexandrite specifically, chromium is the agent responsible for both the body colour and the colour-change effect.) The strength of this shift — how distinct and complete the change appears — is one of the most important value factors in grading alexandrite, alongside more familiar factors like clarity and carat weight.

Discovered for a Tsar

Alexandrite was discovered in 1830 in the emerald mines of Russia's Ural Mountains, where miners initially mistook the green daylight colour for emerald — until candlelight revealed a startling shift to red. According to the most popular account, the stone was identified on the same day as the coming-of-age of the future Tsar Alexander II, and was named in his honour. Its green-to-red colour change happened to mirror the colours of Imperial Russia's military, which only added to its appeal as a national gemstone, and fine Russian alexandrite from this original Ural source remains the historic benchmark against which all other alexandrite is judged — though the original deposits were largely exhausted by the early 20th century, making genuine Russian-origin material a significant rarity today.

Where Alexandrite Comes From

Folklore and Healing Traditions

Although discovered less than two centuries ago, alexandrite quickly acquired its own folklore — particularly in Russia, where its colour change was seen as a striking, almost magical property, and it became closely associated with Imperial prestige. In contemporary crystal traditions it is sometimes linked to balance and transformation, a natural association given its defining optical effect. As with any such tradition, this is a matter of personal and cultural belief rather than a long-established practice, offered here for context rather than as guidance.

How Alexandrite Is Graded

Quality in alexandrite is generally assessed across colour, clarity, cut, and carat weight — with colour and overall character typically the dominant factors in value.

What a Lab Report Confirms

A lab report identifies the species, describes colour, and discloses any treatment. Natural alexandrite is essentially always untreated — its colour-change property is entirely natural, and there is no widely accepted treatment to create or enhance it. Lab-grown (synthetic) alexandrite and colour-change synthetic sapphire/spinel are sometimes sold as cheaper substitutes and should be clearly disclosed as such.

Natural, Ethical, Jaipur-Sourced

Every alexandrite in the Paraiso Jewels vault is described accurately as to its natural or treated status on its label. We source through Jaipur's gem market — one of the world's oldest and most concentrated coloured-stone trading centres — and our stones can be verified at GTL Jaipur, the region's principal gem testing authority.

On request, each piece can be accompanied by documentation covering weight, dimensions, and treatment status. If you have questions about the origin or treatment of a specific stone, contact us via WhatsApp or email and we'll provide full details.