Learning to be a Gem

I gasped as I slowly worked myself in the corner. Who are you? What am I doing here? Thoughts raced through my mind as my heart beat raced as I suddenly stopped. "What are you doing to me!" I shouted my voice cracking with fear.
A glow descended on a weird birthmark I always had. The glow increased to a giant burst of light as a nob appeared. I grasped the collar of my shirt and pulled it down and the birthmark on my shoulder was stilling partially glowing.
The nob was a bright blue collar, curiously, I held hold of it and dragged it out.
A hook sword?
My eyes widened. Turquoise vines wrapped around the handle and the blade was a dark shade of blue, almost a black.
"What's going on..?" I whispered dropping the sword with a clang that echoed.