A lot of MMU has what you might call pure and natural ingredients, but this really depends on what your definition is. For instance, nearly all MMU uses Oxides for colour.
Iron Oxide is a naturally occuring mineral. We commonly call it rust. Obviously we don't want to put rust on our faces, so the yucky bits are removed. Therefore, as it has been processed, in fact, artificially created, can you call it natural?
There are also many things that are entirely man made, that have a greater effect, with milder ingredients. I make hand made soap. I use only ingredients that I consider "pure and natural", ie, organic olive oil, silk, honey, beeswax, etc etc. Now, I love handmade soap, I have found that my skin is better and I use it on my face everyday. Handmade soap has a PH level of around 7 which is fine, but there are people that really can't take to it. Their skin just isnt happy using it. They would much prefer glycerin soap, such as LUSH or glycerin wash bars. These are made from a combination of synthetic materials, but they have a lower PH, and so are milder in some ways. Some even promise not to sting your eyes, where as soap always will!
I am probably boring you to tears, but this is a passion of mine, i make soaps, lotions and cosmetics, and researching ingredients is very eye opening!
Please don't be afraid of oils, some are lovely for your skin, and they don't necessarily mean you will break out. If you have questions about a specific product or ingredient, I am happy to explain it if I can