Turquoise is a bright blue to blue-green mineral and is formed by a combination of aluminum, copper, phosphorus, and water as well as other local ingredients that can affect its color. It is a semi-precious stone, formed over millions of years, and is popularly used in jewelry. There are numerous varieties of turquoise and they are generally known by the location where they were found. It also comes in several shades of blue and green such as sky blue, mid range blues, deep blue, blue-green, vivid green, sea green and leaf green. When valuing turquoise, color and saturation are critical.
