Mineral sunscreen works very intuitively, and feeling that grime makes sense. If you have dark skin, many if not most mineral sunscreens will be quite visible. You're trying to literally cover your skin with a screen and you should be able to feel it and probably see it. You can also wash it off quite easily (to the extent it's a problem at the beach).

Chemical sunscreen that avoids this is designed to sink into the skin like lotion. So there's something literally in your skin blocking uv or it won't work very well. I'd say this increases the odds of circulating something carcinogenic or otherwise toxic into your bloodstream.

TIL that chemical sunscreen does go into the bloodstream: https://www.fda.gov/news-events/fda-brief/fda-brief-fda-anno...

AFAIK Bemotrizinol is the only(?) chemical sunscreen active which is shown to not be an endocrine disruptor (this chemical https://pubmed.ncbi.nlm.nih.gov/36738872/)

It's hard/impossible to find in US formulations but in AU and EU some higher end brands use it. I like the La Roche Posay Anthelios series of sunscreen - I believe they all use Bemotrizinol as the active but I am 100% sure this one does: https://www.laroche-posay.com.au/sun-protection/face-sunscre... - Note that the formulation for the specific product is different in different regions, this is the Australian version.

Recently I went into the whole rabbit hole of sunscreens as I moved to Brazil from Switzerland, and now need to use it everyday (ok I know, theoretically also back home would be nice!). So I bought a mineral sunscreen. It feels "healthier" but also doesn't have that good lotion-like characteristic that you can just apply and forget. I really hope sunscreen companies are able to crack this one up.