The Rarest of all Gemstones

The term "YOGO Sapphire" refers ONLY to sapphires from the Yogo Gulch in Montana. YOGO is said to mean "sky" and sapphire mineral is corundum and very hard.  Sappheiros is a 

ancient Greek work meaning "Blue Stone". Unlike Asian, Australian and African sapphires, YOGOs maintain their brilliance in artificial light and require NO heat treatment. YOGOs present an advantage to gem cutters: since they are found as primary constituent minerals within an igneous matrix, rather than in sedimentary alluvial deposits where most other sapphires are mined. They retain a perfect or near perfect crystalline shape, making cutting much easier, as does their lack of inclusions, color zoning, or cloudiness. YOGOs also exhibit a triangular pattern on the basal plane of the flattened crystals, with thin rhombohedral crystal faces, a feature absent in sapphires from other parts of Montana and around the world.

Yogos tend to be beautiful and because of their rarity, very expensive. The United States Geological Survey and many gem experts have stated that Yogos are "among, if not, the world's finest sapphires." The rough gemstones tend to be small, so faceted Yogos heavier than 2 carats (0.40g) are unusual and highly desired. Only about 10% of cut stone are over 1 carat (0.20g). Because of the rarity of large rough Yogo sapphires, their prices begin rising sharply when they are over 0.5 carats (0.10g), and increase exponentially when over 1 carat (0.20g). Montana sapphires in general come in a variety of colors, but YOGOs are almost always the highly sought after blue that sapphires ae known for. About 2% of Yogos are extremely rare purple or wine colored, due to trace amounts of chromium. A very small number of red rubies have been found at Yogo Gulch and these are even more rare and desirable than purple YOGOs.

A gift of a sapphire symbolizes a pledge of trust and loyalty. It is from this tradition that sapphire has long been a popular choice for engagement rings. Sapphires have so many positive aspects and relate to Heaven, Royalty and Love/Romance, and is the September and Chinese Tiger birth stone, also the quintessential gift for a 45th Anniversary.