What is this stone?

I grabbed this stone pendant as soon as I saw it, fished out a few more that were equally as beautiful, and placed them into my tray, along with my other selections. "What's this stone?", I asked as I was paying for it. Oh geeze....now I can't remember", was the answer, "...but give me time...it'll come to me." Well...whatever it is...it's quite beautiful.

I love it with the leather cord...substantial, casual...and just very good looking. Retail price: $36.00