What does this star icon mean on Genshin Impact's minimap?

These are the collectible items which you can turn into the Statues of the Seven.

They are different depending on the region you are in.

  • Mondstadt - Anemoculus (Small blue winged orb)
  • Liyue - Geoculus (Small orange crystal)

You can gather them and then devote them to any statue you find for increased stamina, adventure exp and other rewards

Sometimes they are hidden, and might require smashing rocks, exploding something or climbing up trees etc.

The example given in the question, I would attack the three piled rocks with a claymore.