There are two kinds of sodium lights: Low Pressure (LPS) and High Pressure (HPS). These lamps are mostly used for street lighting as well as industrial uses. The lamp works by creating an electric arc through vaporized sodium metal.
Enhanced Turquoise. Enhanced Turquoise is a natural stone that has only been treated with either chemicals and heat, or just heat to enhance the color and harden the stone. This type of treatment keeps the color from fading over time and makes more of the harder turquoise available for the market.
Darker shades of turquoise, such as teal have a more sophisticated feel. Variations of turquoise, which often is used to represent water, also is referred to as aqua and aquamarine. Turquoise is a valuable mineral that is often use for jewelry, especially in the American Southwest and Middle East.