The color changes depending on how the light hits it, a characteristic of opal, adding a special accent. The approximately 5.5cm size is a classic design that matches most ties. This was hidden away in my father's dresser. It seems he bought it on a trip to Australia a long time ago, so I believe the opal is genuine. However, please understand that it has not been appraised. m(_ _)m You might consider having it remade into other accessories ♬ The case is broken and will not be included. I will give it to someone who can use it ^_^ I'm sorry, but I can't offer a discount m(_ _)m