Winza Ruby Crystal 13.75ct,Dimensions = 15.00 * 12.00 * 12.00mm,Natural and Untreated,Crystal Growth in Amphibolite Facies,Specimen was sourced from Winza, Tanzania,More Information from the Following Link:https://www.gia.edu/doc/Winter-2008-Gems-Gemology-Rubies-Sapphire-Winza-Tanzania.pdf