Synthetic Alexandrite – Lab-Created Chrysoberyl
Appearance & Properties
Synthetic alexandrite is lab-created chrysoberyl, with essentially the same chemical composition and crystal structure as natural alexandrite. Its characteristic colour change is usually green to bluish green in daylight and red, purplish red or raspberry tones under incandescent light. The effect is caused by chromium absorbing selected parts of the light spectrum; it is not the same as chatoyancy, the moving band seen in cat’s-eye gems. Material can be transparent to translucent, and may show pleochroism, meaning different colours when viewed in different crystal directions. Chrysoberyl measures about 8.5 on the Mohs scale and has no prominent cleavage, giving it good everyday durability. Internal features and colour-change strength vary with the growth method.
History & Discovery
Natural alexandrite was identified around 1830 in the Russian Urals, in an area associated with emerald mining. Mineralogist Nils Gustaf Nordenskiöld is commonly credited with recognizing the unusual material, although early accounts differ in detail and the chronology of its naming is not certain. The name alexandrite became associated with the future Russian emperor Alexander II and with the stone’s green-and-red colour change, which recalled imperial colours. Natural material remained exceptionally scarce, encouraging scientific efforts to reproduce its colour-changing properties. Commercial synthetic alexandrite appeared during the twentieth century, using methods such as flux growth and crystal pulling. It is a genuine lab-created form of chrysoberyl, not merely coloured glass or another imitation.
Occurrences
Synthetic alexandrite does not occur in geological deposits: it is grown in controlled laboratory conditions. Its raw materials and growth processes may produce crystals with appearances similar to natural stones, but that does not give them a mine origin. For comparison, important natural alexandrite localities include the historic Tokovaya area in Russia’s Urals, Sri Lanka, and deposits in Brazil, Tanzania, Zimbabwe and Madagascar. Natural stones from these regions can differ considerably in colour, clarity and strength of colour change. A stone’s appearance alone cannot reliably establish its origin. Laboratory-grown alexandrite should therefore be described as synthetic, while natural alexandrite and treated natural material require separate identification.
Famous Examples & Interesting Facts
One well-documented reference is a 65.08-carat faceted natural alexandrite held in the Smithsonian’s National Gem Collection; it is often cited among the largest cut examples on public display. It is not synthetic and should not be confused with laboratory-grown material. A useful fact about alexandrite is that its colour change depends strongly on the light source. Daylight rich in blue and green wavelengths can make the gem appear green, while warm incandescent light, richer in red wavelengths, can bring out red or purplish tones. The most attractive change is not necessarily a complete reversal: many gems show intermediate colours and varying degrees of transition.
Jewellery & Use
Synthetic alexandrite is suitable for rings, earrings, pendants and other jewellery, and it is often cut in shapes that show colour change clearly, including ovals, cushions, rounds and mixed cuts. Facet arrangement, body colour and viewing direction all influence the effect. With a Mohs hardness of about 8.5 and good toughness, chrysoberyl is practical for regular wear, although sharp impacts can still chip a facet edge or damage a setting. Clean it with warm water, mild soap and a soft brush. Avoid sudden thermal shock, harsh chemicals and abrasive cleaners. Steam or ultrasonic cleaning should be used only when the stone and setting are known to be suitable. Synthetic stones, treated natural stones and imitations are distinct categories.
Symbolism, Astrology & Tradition
Alexandrite is widely used as a modern alternative birthstone for June and is traditionally associated with the 45th wedding anniversary. In Russian historical symbolism, its green-and-red colour change has been linked with imperial colours and national identity. Some modern jewellery traditions describe the gem as a symbol of transformation, adaptability or balance between opposites; these are symbolic interpretations, not scientific properties. Alexandrite is also assigned to different zodiac signs in contemporary astrology, but there is no single universally accepted correspondence. Crystal-healing and energy claims sometimes attached to alexandrite belong to esoteric belief or folklore and have not been established by medical science. Synthetic alexandrite can share the symbolism of the gem name without being a natural stone.