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 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.

I'm best pals with salt, If you sneeze, it's probably my fault. I can also be green, yellow or red. Or so spicy your taste buds will be dead. What am I?

Some claim these aren’t real. It took Alfred Hitchcock to make them scary. Spelled differently, they turn, turn, turn