Synthetic Alexandrite – Bagdasarov

synthetic alexandrite hdsm

Alexandrite is one of the most amazing stones.

Buy natural alexandrite in our shop

Synthetic Alexandrite

The main difference between alexandrite and other gemstones lies in its unique ability to change color depending on ambient light. Alexandrite has a bluish-green or grass-green color when white fluorescent artificial lighting is used, but turns violet or ruby-red in sunlight or candlelight.

This is called the alexandrite effect phenomenon, and is commonly used with other minerals that are able to change color. For example, garnets, which can change color, are also called garnets with alexandrite effect.

Alexandrite is a variety of the mineral chrysoberyl. The unusual color change effect is due to the presence of chromium ions in the crystal lattice. Currently, natural alexandrite is recognized as one of the most beautiful and rare gems.

Of course, this led to the appearance of forgeries in the market, which only remotely resemble the original stone as they fail to reflect the great color changing effect and light play inside natural alexandrite. Corundum forgeries are very widespread.

Bagdasarov modification (HDSM)

Synthetic alexandrite “Horizontal directional solidification method” created by Kh.S.Bagdasarov in 1964 was new radical idea of single crystal growth based on moving a crucible with the raw material and a single crystal seed in the horizontal direction.

This method was created for the growth of large-size, Nd doped, high-perfect yttrium-aluminum garnet laser crystals. It turned out to be very efficient for stone growth too creating crystals with previously unseen surface areas. Using the HDS method issues of synthesis of large and especially large plate-form refractory leucosapphire single crystals were solved.

The HDS methods growth process consist of the following process’s

Seed (with any require crystal orientation) is installed at the front tip of the container which resembles a ship in a horizontal position.
The raw stone material is placed in the container.

The container is placed into a furnace.
The growth process is done in a vaccum or inert atmosphere.
During the growth process via a camera which is located on the top of the furnace, the process is being followed and diagnosed during the full duration of the growth process.

The melt is then slowly cooled.
This method makes it possible to get large slabs with almost perfect edges and of any given crystallographic orientation: C-plane, M-plane, R-plane or A-plane.

Bagdasarov stones has a very high optical quality and is suitable for very demanding optical, mechanical, RF and LED applications.

The HDSM method allows to carry out repeated crystallization in case when additional chemical purification of the raw material is required. It is also possible to carry out a continuous crystallization process by directed shift of the crucible echelon through the crystallization zone.

While realizing the HDSM method it is technically easy to create a controlled temperature field that is extremely necessary for growth of high-perfect large-size single crystals. This method makes it possible to get large slabs with almost perfect edges and of any given crystallographic orientation.

Synthetic alexandrite – Bagdasarov

  • Chemical formula: BeAl2O4:Cr3+
  • Crystal system: Rhombic
  • Hardness (Mohs): 8.5
  • Density: 3.7
  • Refractive index: 1.741-1.75
  • Dispersion: 0.015
  • Inclusions: Inclusions free. (key separation from natural Alexandrite: Fogs, cracks, holes, multi-phase inclusions, quartz, biotite, fluorite)

Natural alexandrite for sale in our gem shop