Pulled Czochralski Alexandrite (Color Change)
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Lab Created Alexandrite – Pulled Alexandrite – Czochralski Pulled Alexandrite – Synthetic Alexandrite
Alexandrite is known as “emerald by day, ruby by night”.
Alexandrite is a beautiful rare stone and its magic of changing colours make it a must have for all stone lovers. The very name of this gemstone brings to mind images of royalty .It shows both red and green as principal colors ,the principal colors of old Imperial Russia making it the national stone of tsarist Russia.
The Russian created alexandrites are grown from chrysoberyl crystals and unlike lab corundum, these Czochralski Pulled Alexandrites actually closely resemble the natural mined stones in many ways. They are grown in a controlled environment to exhibit perfection.
Alexandrite is a type of chrysoberyl, a rare oxide mineral and the hardest ,most durable gemstones you can find. Alexandrite is scarce owing to its unique chemical composition as in addition to iron and titanium, it contains high quantities of chromium as an impurity, partially replacing aluminum.Due to this impurity spectacular green hues of this June gemstone can be seen.
How Pulled Alexandrites are grown in lab?
These Synthetic Lab created alexandrite mostly grown by Czochralski method (pulled alexandrite) and by floating-zone method. The Czochralski process, or pulled alexandrite technique, is a method of crystal growth used to obtain crystals (especially rod-shaped single crystals), metals and salts. The process starts with melting the materials of appropriate composition in a crucible. To make alexandrite crystals by Czochralski method, beryllium and aluminum oxides were melted together in a crucible with addition of vanadium, chromium and ferric oxides. A seed crystal mounted on a rod is immersed into the melt where it starts to rotate. The crystal’s rod is then pulled upwards slowly and rotated at the same time. By precisely controlling the temperature gradients, rate of pulling and speed of rotation, it is possible to extract a large, single crystal from the melt.
Then our specialist engineers cut these stone from rough to get best lab created alexandrites making it to have same composition as real alexandrite.
Chemical Properties –
- Chemical composition: BeAl2O4
- Hardness: 8.5
- Color: green in daylight and red-violet in incandescent light.
- Luster: vitreous to greasy
- Transparency: transparent
- Fracture: conchoidal, brittle
- Alexandrite Index of refraction: 1.745 – 1.759
- Molecular Weight = 126.97 gm
At Gems N Gems lab created pulled alexandrite are available in all shape and size making it very popular among jewelers