What minerals have the most bacteria in them?

For a school project I'm doing "Why the minerals in the iPhone matter". My main topic is how they trap bacteria the most and can cause acne breakouts in your skin. I know what minerals are in the iPhone but I don't know which ones are the most germy. Can someone tell me in general what minerals trap the most bacteria? Also here are the minerals in the iPhone (that we're using) so you can tell me if any of them trap bacteria the most.
- Yttium
- Lanthanum
- Praseodymium
- Europium
- Gadolinium
- Terbium
- Dysprosium
- Cerium

So you don't let contaminates skew the results, I recommend that you start soaking your head in pickle-brine every night.

There's no relation. It depends on the shape and texture, not materials. And you get your data with a smear test, not by polling strangers on the internet.