The most vivid blue Sapphires on earth and the most brilliant are from Yogo Montana. The Sapphires mined at the turn of the century from this location are thought to be even brighter. Very few Sapphires can claim to be authentic natural no heat Yogo Montana Sapphires. These Sapphires can. Certified by the AGL these bright blue Yogo's are amongst the best we have seen. 3.5 x to 3.7mm each. Original 1910 to 1920 bar pin in 14k yellow gold filigree. Excellent condition, no repairs or defects. Catch stamped A+A. This is a very rare fine vintage Victorian style pin. 4 AGL certified (#CS80699) natural corundum Sapphires genuine Montana Yogo gulch 3.5mm, approx. total weight 1.00ct. Tested: 14k. Stamped: A+A. 4.8 grams. 11/16 x 1/4 inch.