The top lot among colored gemstones was a Burmese oval ruby weighing 18.86 carats, which achieved a final price of more than $5 million, well above its $4.2 million high estimate. Art Deco jewels ...

Sapphire is another form of corundum. It comes in various colors, including blue, pink blue-violet, blue-green and combinations of these colors. Blue sapphires contain iron and titanium.

When you hold up a crystal prism to a beam of light, you see red, orange, yellow, green, blue and violet and every color in between coming out the other side. But where does pink fall? Colors look ...