'The 69.99 ct blue sapphire described in GGL report no. 11100120 which was named ''
The Royal Blue Wonder of Mogok'' by its owner, is an exceptional rarity. In addition to its size, it displays a distinctive and richly saturated blue coloration combined with high degree of transparency. Of principle importance, this outstanding gem has not been exposed to thermal enhancement techniques.
Such a combination of remarkable characteristics is very rare in Burmese sapphires of this large size.'
Excerpt from the Gübelin appendix letter.