it shouldn't but what I found with the Tibetan silver is if left in a jewelry box with silver plated things for a long time it can tarnish, it'll never turn your finger green but can tarnish around other metals over time...hope that helps...I keep all my rings separated for that reason
I believe it's Green Chalk Turquoise. But I'm not 100% on that...But the cabochon in the ring is gemstone weight and quality, just not sure which one... sorry