Everyone loves me, but only the lucky ones can have me.

I'm indestructible, but only with my own family.

Many got killed because of me, serpent being killed to get me but no success until today.

I live underground, but can be seen on earth.

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This has gone through the [sandbox](http://meta.puzzling.stackexchange.com/questions/5276/the-riddle-sandbox/5296#5296).