Please be weary when buying Mac Pigments from the UK as there are certain people selling fakes here are a few things to look out for:
Dont trust listings with professional studio pictures.
Fake Pigments have a thicker base of the jar
Be weary when the box is not shown in the picture and when it is look for misprints.
Look at the back of the box. The genuine box says;
POLVOS CON PIGMENTOS
The fake box says;
POLVOS CON PLGMENTOS
If in any doubt have a look at the forum at specktra