Have you ever heard of mica? It's a mineral that can be found in almost every makeup product out there! It's also often used in soap. It has a shimmery effect, which makes it a great candidate for eyeshadow. When inhaled, mica can be really dangerous because it can cause scarring on your lungs. This likely isn't a huge problem for you as a consumer because you'd need to inhale quite a bit of mica over repeated periods of time. However, this DOES present a problem for the workers of mica mines.
Not only can the inhalation be a safety hazard, many mica mines use child labor and are also operating illegally. Much of the world's mica comes from India in the "mica belt" where mica is abundant. These mines are in areas of forest protection which is why they're operating illegally. Because of this, there's no way to regulate the labor conditions. They use children, pay unfair wages, and don't have any safety regulations. After mica is mined, it goes through many hands before making it into your makeup. It's hard to know if your favorite company is sourcing their mica from a legal, safe, fair mine. There's really no way to know, unless they explicitly state that they source their mica ethically.
If you're interested in learning more about the ethics of mica, check out this article. Next, check out this article (there's a great video in this article too).