Search
Montana Sapphires
Specimen | Catalog Number | Locality | Weight |
---|---|---|---|
Corundum (var. sapphire) | NMNH G3365 | United States, Montana | 153.20 ct |
This colorful assortment of sapphires was recovered from the gravels of the Missouri River bars near Helena, Montana. They range from about 0.1 to 2.5 carats.Sapphires are a variety of the mineral corundum. Pure corundum is colorless, but chemical impurities in the crystal structure can impart a range of vivid colors. Although commonly thought of as blue gems, sapphires exist in a variety of colors as seen here. Iron and titanium are responsible for the blue color of sapphires. Sapphires other than blue are called "fancy-colored" and range from pink, yellow, and orange to purple, green, and even black.