The Optoelectronic Crystal Materials and Device Laboratory of the School of Physics of Nankai University recently produced an pale purple colored synthetic gemstone, a single crystal of Al2O3.

Pale purple colored synthetic rough gemstone

The single crystal of Al2O3 has a melting point exceeding 2,000 degrees Celsius and its Moh’s hardness is next only to diamond. It comes in a variety of colors as it has different components. Except for the red ones known as ruby, other colored Al2O3 are collectively referred as sapphire.

A crystal growth device developed by the Optoelectronic Crystal Materials and Device Laboratory

A purple colored sapphire is extremely rare in nature, and a discovery of a near-pale-purple-colored gemstone has yet to be reported. When the pale purple colored sapphire is produced in the lab, it requires a high temperature over 2,000 degrees Celsius for its synthesis. The gemstone features highly concentrated and complicated coloring elements and an extremely expensive heat-resistant iridium crucible is needed for its production. It is an intricately crafted item with low yield and high cost. The Optoelectronic Crystal Materials and Device Laboratory, with its expertise gained from long-time research on high-performance optoelectronic crystals, collaborated with Huiyouge (Tianjin) Culture Communication Co., Ltd. and other partners to make technological breakthrough. After solving many technical problems such as crystal growth device development, thermal field design, crystal growing process, chromaticity control and defect control, they successfully achieved high quality production of the pale purple colored and nearly 15,930-carat synthetic gemstone.

A comparison of the pale purple colored synthetic gemstone after cutting and the theme color of Nankai University

Pale purple is the theme color of Nankai University, known as Nankai purple. As this year marks the centennial anniversary of the physics discipline of Nankai, the Optoelectronic Crystal Materials and Device Laboratory and its partners donated the pale purple colored synthetic gemstone to the School of Physics as a special gift to mark the occasion.

(Edited and translated by Nankai News Team)