If you have me, I‘m inside your head, If I‘m a bad one, I might cause you to be dead, OP had to have me to be able to post this riddle, I have an even number of letters, so there‘s no single letter in the middle. What am I?

I’m born in the depths where no light ever gleams, Then rise to escape in a sigh or a scream. Some blame me, some claim me, some flee my offence I slip past your guard with a puff of suspense

Old becomes new in a cyclical dance, Transforming waste for a second chance. From bottles of plastic to cans of aluminum, Save resources, help the planet and have some fun.

I sparkle bright in gold or blue, a precious gem, but not brand new. Found in rings and royal flair, What stone am I, with regal air?

Spin me around and watch me glide, On a peak where dreams reside. A small word, but it stands tall, Often the target of ambition's call.