Cabochon ring

So later in the evening I tried out a cabochon ring. I don't know what stone this is. Any ideas anyone? It looks and feels very peaceful. Even wearing this ring feels that way...peaceful calm vibration to it. The ring is made in Brass. I wish I had made it in gold so it wouldn't tarnish. I have no problems with wearing brass....except it tarnishes. Sigh! I don't think this will be on sale...I feel this ring is mine. :-)