Please see my review on Make Up For Ever Aqua Liner #11 Diamond Burgundy here for more of my thoughts on the formula.
From Make Up For Ever's website:
High Precision Waterproof Eyeliner
Aqua Liner is a high precision waterproof liquid eyeliner. Rich in pigments and polymers, its formula guarantees intense color and an outstanding waterproof result. Its ergonomic applicator lets you easily apply an ultra precise line to create an eyeliner makeup look. Aqua liner is available in a wide range of vibrant shades with matte, iridescent and diamond finishes. Easily remove with waterproof makeup remover.
#7 Diamond Black Purple is a beautiful shimmering, iridescent blue toned purple. Sometimes in swatches on my skin it can look quite blue but in use on the eye it reads more purple as you will see in a quick face of the day post I will feature shortly.