This article states that iron oxides can help to protect the skin from visible light which can cause hyper-pigmentation so I decided to make myself a loose powder using 10% iron oxides (red, black and yellow). I used Corn Starch as my base (approximately 70%) along with Zinc Oxide (approximately 20%). Corn Starch and Zinc Oxide both have skin protecting properties so I'm hoping that they will help to protect my skin from the environment. I plan to use the loose powder on top of my foundation to absorb some of the greasiness.