Seal or not my flagstone coping

I have quartzite flagstone coping. When dry it looks very dull and not very colorful. When wet, it is beautiful. We will also be incorporating flagstone into parts of the decking. It has been suggested to me to that if I seal the flagstone, it will get the same darker look that would pull the color variations out.

What is everyone's opinion of sealing the quartzite flagstone. Will this produce the look I am going for or not? I do know it has be maintained every year or two.

Let me know...

Seal or not my flagstone coping