https://www.gia.edu/JP/gems-gemology/winter-2015-sapphire-ruspoli-sapphire-historical-gemological-discoveries
The Grand Sapphire of Louis XIV and The Ruspoli Sapphire | Gems & Gemology
Archival research and gemological characterization reveal the true story of this 135.74 ct blue sapphire from the French crown jewels.
the grand sapphirelouis xivruspoligemsgemology