400-year-old diamond might be worth USD4mil

Sotheby’s is going to auction a 400-year-old diamond and it is expected to be worth up to USD4 million.

A foreign news agency reported that the diamond which is known as the ‘Beau Sancy’ is one of the world’s oldest known diamonds and weighs 43.98 carats, adding that Beau Sancy will be displayed in Paris, London and Zurich until it goes up for auction in Geneva on May 14. The Beau Sancy once belonged to France's Queen Marie de Medici and was originally cut from a gem mine in the Indian city of Golconda. It was owned by the last Emperor of Germany, Wilhelm II, before being acquired by a private European owner.

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The Beau Sancy is said to have its name from 16th century French financier and diplomat Nicholas Harlay de Sancy. The gem is described as a "perfect, colorless, rounded pear-shaped diamond."

RUBY TREATMENTS

TREATMENT (Enhancement): Any human-controlled process, beyond cutting and polishing, that improves the appearance, durability, or value of a gem.

The list of popular gems routinely treated includesamethyst,aquamarine, chalcedony, citrine, emerald, jade, lapis lazuli, opal, pearl,ruby, sapphire, tanzanite, tiger’s-eye, topaz, turquoise, and zircon. 

Ruby is one of the gems that are routinely treated, there are over 90% of rubies in the trade are treated.
The common enhancement of rubies are:
Heat treatment
Fracture Filling
Lattice diffusion

Lead glass fracture-filled rubies

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