To keep it simple, chrome nail powder is typically made up of very fine aluminum. The aluminum powder is then 'dyed' to create different colors. The aluminum powder is very reflective and when rubbed over surfaces, creates a mirror-like sheen. Aluminum powder is used in many different industries such as car paint, cosmetics, decorations, and more. The pigment itself can be expensive due to extensive manufacturing needing to extract the aluminum and grind it into powdered form.
How are chrome nails applied?
Chrome nails are created when a chrome pigment is rubbed over a darker nail color. The dark color helps reflect the light of the pigment, creating a gorgeous, mirror-like sheen. If you try to use a lighter color beneath, the color will not come through as well.
Only within the last few years has chrome nail powder increased in popularity. Many nail salons still do not offer chrome nails as an option.
Most chrome nail powder brands mix chrome pigment with acrylic powder and/or glitter to create a color that can be used as a dip, acrylic, and a chrome finish. Some people buy just the pigment and are confused when they can't use it as a dip/acrylic as well, because both the stand alone pigment and dip/acrylic powder is marketed the same. If you're buying just the pigment, you'll usually find them in very small 1g jars, while dips and acrylics are sold in 10g+ jars. Fairy Glamor sells dip and acrylic chrome nail powder colors in 15g and 1oz jars.
How to protect chrome nail powder from smudging.
In most cases, chrome nails need to be sealed with a top coat to prevent the powder from smudging or rubbing off. It does not change the color of the nail polish beneath it--instead, it sits on top like a thin blanket.
For an in depth tutorial, you can read more on how to do chrome nails here.