Sapphire and diamond ring

The oval sapphire weighing 21.99 carats, flanked by 2 half-moon-shaped diamonds weighing approximately 1.70 carats, mounted in platinum, size 6¼.

Accompanied by AGTA report no. 98000410 stating that the sapphire is of Burmese origin; no indications of heating. Also accompanied by Gubelin report no. 0708566 stating that the sapphire is of Burmese origin; no indications of heating, and the comment that this colour variety of sapphire may also be called "royal blue" in the trade. The flanking half-moon cut diamonds are approximately H-I color and VS clarity. In very good condition.
In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective qualified opinion. Illustrations in the catalogue may not be actual size. Prospective purchasers are reminded that, unless the catalogue description specifically states that a stone is natural, we have assumed that some form of treatment may have been used and that such treatment may not be permanent. Our presale estimates reflect this assumption.
NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING CONDITION OF A LOT, ALL LOTS ARE OFFERED AND SOLD "AS IS" IN ACCORDANCE WITH THE CONDITIONS OF SALE PRINTED IN THE CATALOGUE.

Accompanied by AGTA report no. 98000410 stating that the sapphire is of Burmese origin; no indications of heating.

Also accompanied by Gubelin report no. 0708566 stating that the sapphire is of Burmese origin; no indications of heating, and the comment that this colour variety of sapphire may also be called "royal blue" in the trade. 

The Gubelin report also includes a separate information sheet to trade color terms for "royal blue" sapphires:

"As in the rich and sumptuous description of the blue sapphire colours to follow Dr. Eduard Gubelin endorses that the royal blue sapphires are among the most precious and coveted. Near to every shade of blue can be found in the world of sapphires - from dense, dark gentian blue to crystal-clear ice blue, from dancing, frivolous azure blue, through pale, cheerful sky blue to crackling, exciting electric blue. One's vocabulary seems too paltry to do justice to the many possible variants of blue. Though in spite of all these varieties of blue gems, one of the most treasured and sought-after is the enchanting beautiful royal blue sapphire - deep and luscious, as unfathomable as a mountain lake. 

Many famous stones such as the Rockefeller Sapphire are of this intriguing shade of blue. The highest quality sapphires from the  famous mines in Mogok, Burma, are typical representatives of the precious royal blue colour."

To possess a Royal Blue Sapphire is like being the keeper of  "tears from the eyes of the goddess Saitya."
(The Color Treasury of Gemstones, Dr. E. Gubelin)