This is a REAL M.A.C eyeshadow...
This is a FAKE M.A.C eyeshadow..
So from my observation..
The real M.A.C eyeshadow generally feels much better quality compared to the fake one. The two eyeshadows, although they claim to be the same shade, look completely different. The packaging of the real eyeshadow is a slightly sparkly graphite colour, whereas the fake one is a solid black. The fake one also feels a lot heavier then the real one. On the top on the packaging M.A.C is printed much thicker on the fake one and the clear plastic which is slightly curved on the real one is flat on the fake one. The real eyeshadow has a graphite sticker on the bottom which has printed on it the colour and the texture (matt, pearl etc), the fake eyeshadow has a plain black sticker with another smaller sticker over the top which has the colour printed on it along with a number... (M.A.C would never do this). The two boxes are very different also, not only is the font slightly different but the text on the side where the ingredients are located have been printed in different places. The real one takes up mostly all of the side whereas the fake one has been printed in the centre. Also they contain completely different ingredients. The barcode is another thing which is very different: the fake one has a white box around it and the real one does not. The box for the fake one was also very cheap and as shown in the pictures it completely fell apart. The biggest giveaway that the second eyeshadow is fake is the little mirror and sponge applicator which are in the bottom of the eyeshadow... M.A.C have never sold eyeshadows in packaging like this, not only that but the mirror and applicator are also very cheap feeling.
Hopefully these pictures can help you to avoid fake M.A.C, there could be any kind of chemicals in the fake eyeshadows that may be very damaging or toxic. M.A.C products are pricey because you are paying for the guarantee of quality and reliability. I bought this fake eyeshadow from eBay, which I not recommend. There are so many fakes online and I suggest that if you wish to buy M.A.C online that you use a trusted website like the M.A.C website or somewhere like Debenhams or House of Fraser.