Heat Treatment

Heat Treatment

Heat Treatment Introduction Gemstones are colored because certain wavelengths of the visible spectrum of electromagnetic radiation get absorbed while other wavelengths are transmitted. Which wavelengths are absorbed depends on the physical and chemical properties of...
HPHT

HPHT

HPHT HPHT treatment stands for high pressure – high-temperature treatment. This method of diamond enhancement, invented in the late 1960’s, started to be applied commercially during the late 1990’s. It involves the heating of diamonds under high...
Imitation

Imitation

Imitation Paste Used to Imitate Yellow Natural Gemstones in Costume Jewelry. An imitation is an object or gemstone which is used to mimic a more valuable object or gemstone. Many synthetic and natural minerals are used to mimic – for example – diamond....
Irradiation

Irradiation

Irradiation In 1904 William Crookes, a well known physicist discovers that diamonds turn green upon exposure to radium. The diamonds stayed radioactive and were therefore unfit to serve as jewelry stones. But… the concept of color change due to radiation had been...