Swiss Blue Topaz Cushion 6 ct VVS

Type: Topaz
Weight: 6 ct 1 gem
Size:(avg.) 15.7 x 15.8 x 13.1 mm
Shape: Cushion-Cut
Color: London Blue
Clarity: VVS-VS
Treatment: Irradiated
Origin: Brazil

Topaz is mined from several countries around the world. Blue colored natural topaz is very rarely found. The dark, greyish blue coloration, or “London blue”, of these natural topaz gemstones results from a standardized radiation treatment that requires 3-4 years to produce the deep blue coloration.

ORIGIN: Brazil, Afghanistan, Australia, Myanmar (Burma), China, Germany, Japan, Madagascar, Mexico, Namibia, Nigeria, Pakistan, Russia, Zimbabwe, Sri Lanka, Ukraine and the USA.

CHEMICAL COMPOSITION: Al2SiO4(F,OH)2 Fluor containing aluminium silicate.

TREATMENT: London blue topaz is typically produced by exposure to radiation in a nuclear reactor. When topaz is exposed to fast neutrons, the radiation changes the color centres, producing the deep blue color. Subsequent heat treatment is often used to lighten the inky color. Material treated in this way is likely to be radioactive and may require several months of storage before the radioactivity decays to safe levels.

BIRTHSTONE: London Blue Topaz is the traditional birthstone for December.