The MAC mineralized skinfinishes are a soft powder with a metallic finish that, depending on the shade, can be used on the cheeks or all over the face. But because they do have such a metallic to them, I would just use them around the cheek area to avoid looking like a disco ball. They work much better as a highlight, blush, or bronzer while adding that extra bit of something special.
The two mineralized skinfinishes that I picked up were the following:
Redhead is a golden pink blush or highlighter color (depending on your skin tone) that includes four different strips of color to create that beautiful pinkish gold. The four colors are champagne beige, deeper champagne, peachy beige, and bronzy pink. Similar to the Bobbi Brown Shimmer bricks, you can use these individual strips of champagne colors as shadows if desired.
Blonde is more of a rosy pink blush color that also includes four strips of different colors to create that rosy pink shade. The four colors are light pink, peachy pink, rosy pink, and dark rosy pink. Because Blonde is more of a true rosy pink blush, I would probably avoid using any of the separate colors, other than the lightest pink shade, as a eye shadow.
Even though the texture of the mineralized skinfinishes are incredibly velvety, soft, and smooth, the metallic finish is not forgiving on pores and dried skin. The texture and finish of the skinfinishes do emphasize the problem areas, so it might not be the right product for you if you are concerned with imperfections or the texture of your skin. It's not incredibly noticeable where people would see and point out, and it does still photograph beautifully, so it might be a nice product to have for those once in a while occasions where you want that extra glow.
Both of these products are re-promotes, so although you cannot find them on the counters or in MAC stores now, you might want to check your local CCO, or just keep an eye out for another re-promote in future collections.