sapphire color

[diamondsrock]

I was wondering if it is possible for a natural sapphire to change color after cleaning. By this I mean become darker. I purchased a sapphire and diamond band and accidentally left it in the ammonia solution in the ultrasonic for longer than I intended. Now it is cleaner but the sapphire appear darker. Does ammonia harm sapphires in any way or could they just seem darker because they are cleaner? This was a couple of weeks ago and they still seem darker. They are blue, by the way. Thanks!

 

[Michael_E]

If there was a light colored film on the pavilion, then cleaning the film off of the stone can cause the stone to look significantly darker. This is particularly true if the stone was cut on the shallow side. If you clean a stone that is cut so that it has a large window, then cleaning the window will let you see through it to the dark area under the stone, making the stone look darker.

 

[diamondsrock]

Thanks for your help! That is really interesting.