Trace elements of atomic particles like chromium or iron can cause the corundum to appear in different colors. The formation of corundum with chromium and iron as neighboring deposits is what gives corundum its red color - or what you're likely familiar with as a Ruby. That's right, a Ruby is actually a red colored sapphires! Elements such as iron and titanium cause the mineral to have a blue color!The more trace elements within the mineral, the richer the color. Below is a table of common sapphire colors as well as the specific atomic elements which influence the color.

You may be familiar with the 4 C's of diamonds, but wondering what's the grading system, for a sapphire? The color of a sapphire is measured by its hue, saturation and tone (vivid, strong, medium, slight) which refer to the richness and shade of color if a sapphire.

Just like a diamond, gemstone's such as corundum entrap pieces of the Earth's mantle and sentiments within its formation. Although clarity is not as important in corundum, it does play a factor in selection.

Sapphires, unlike diamonds, are commonly treated in order to maximize the color or clarity. The most common treatment type is Heat Treatment, which uses heat to permanently enhance or lighten the color of the corundum. There are also treatments such as fracture filling which infuses a cobalt rich form of glass into cracks of a lower quality gemstone to improve its overall look, but this is not a permanent treatment.