The red stripe things are redstone! Somewhat useful, but you usually get a lot from one and there are not many uses. I recommend mining them anyway, because often you can find something else nearby (idk if it's an actual game mechanic or if it just feels like it but I often find iron by mining the redstone). The gold stripes is gold, and you need an iron pickaxe to mine both! (Stone might be enough for redstone? I'm not sure, you can probably test it sincw redstone is not very rare)

Very cool- 

I mined a bunch of redstone and then got killed by lava before I could put it in a chest, so I’m gonna have to go get more