How is magnesium found in nature and does magnesium burn?

i'm doing a science project about magnesium
and i want the answers for the follow:
how is magnesium found in nature
does magnesium burn
What are some of the most common uses
and
is magnesium a valuable element?(does it cost a lot to buy/mine, or is it necessary for human life)
please don't copy the answers from a website and please don't answer if you do NOT actually know the answers.