A naturally trusting person of generous spirit, there are, I admit, times when a curmudgeon sits on my shoulder whispering cynical and distrustful ideas in my ear. This often happens when I am confronted with mineral make up. Don't get me wrong, there are some good ones on the market. Sadly, there are many more that are hitching a ride on a bandwagon.

First of all, just because its mineral doesn't mean it's all natural with only the kindest of intentions. In fact, many mineral cosmetics contain additives and irritants, they are difficult to apply and can make dry and aging skin look, well, dry and old.

More worryingly, some mineral powders contain a pearlizing agent that gives mineral makeup that candlelight glow. This agent is bismuth oxychloride. Strictly speaking, it is a mineral, but it's not found in the earth. Bismuth is a byproduct of lead and copper processing. Bismuth oxychloride is also frequently used to bulk up or bind products and is considered a skin irritant and, in large amounts, can cause cystic acne. It is to be avoided if you have acne, rosacea or sensitive skin.

Now, there are even minerals that should be avoided. Take talc, for example. It is widely used in make up. It is closely related to the potent carcinogen asbestos, according to the Cancer Prevention Coalition. In particular, there are numerous studies linking it to ovarian cancer (although there are some studies that contradict this and it should be noted that culprit is body powder made of talc).

Mica, zinc oxide and titanium dioxide are the core minerals in mineral makeup. The thing is though, they have been used in cosmetics for years, long before marketing departments decided to repackage them as something new and 'natural'. Having said that, zinc oxide and titanium dioxide are anti-inflammatory and a good choice for those of sensitive skin.

There are some good mineral makeup brands that take care to keep their products pure. In the next post on this subject, we'll round up some of them.