1.Raw Material Melting:The gemstone's raw materials (e.g., aluminum oxide Al2O3 and dopants) are placed into a
high-temperature-resistant crucible (e.g., iridium, molybdenum, or graphite crucibles) and heated to extremely high
temperatures (e.g., synthetic ruby requires heating above 2050℃) using induction coils or resistive heating until
completely melted.
2.Contact and Crystallization: A small, oriented natural or synthetic gemstone seed crystal is slowly lowered and brought
into contact with the melt surface.
3.Pulling and Rotation: Under strictly controlled conditions, the seed crystal is slowly pulled upward while simultaneously
rotating. The melt at the interface between the seed crystal and the melt continuously cools and crystallizes according to
the crystal structure of the seed, thereby growing a single crystal gemstone with the same orientation as the seed.
4.Process Control: The entire process requires precise control of temperature gradient, pulling rate (typically 6-15
millimeters per hour), and rotation speed to ensure uniformity and quality of crystal growth.
Common steps in the process include "necking, shoulder expansion, diameter control, and tailing" to optimize the crystal
structure.
Gemstone crystals grown by this method exhibit high optical homogeneity, low dislocation density, and can be grown to
large sizes.
It is one of the primary production methods for high-quality synthetic gemstones, especially corundum family gems.