Natural Sapphires
An uncut/rough yellow sapphire found at the Spokane Sapphire Mine near Helena Montana.
The sapphire is one of the two or three gem-varieties of corundum, with another one being the red or deep pink ruby. Although blue is their most well-known hue, sapphires are made up of any color of corundum except for red (red ones are called rubies).
Sapphires may also be colorless, and they are also found in shades of gray and black.
The cost of natural sapphires varies depending on their color, clarity, size, cut, and overall quality - as well as their geographic origin, oddly enough.
Significant sapphire deposits are found in Eastern Australia, Thailand, Sri Lanka, Madagascar, East Africa, and in North American at a few locations, such as at "Gem Mountain", and in or near the Missouri River in the region around Helena, Montana.
Sapphire and rubies are often found together in the same area, but one gem is usually more abundant.