Answer:
Born in the ocean and white as snow. When I fall back to water, I disappear without a trace. What am I?
Who is the most foreign visitor you could imagine?
When I get closer my tail grows longer but when I go away my tail leads the way.
I am constantly overlooked by everyone but everyone has me.
I am the minerals vital for your good health.
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.