Light Purple stone identification?

[Sunseeker888]

Hello all! I came across this 925 sterling silver antique ring with an unknown, light purple translucent stone. I believe this to be a lady's ring, judging by the setting.
Anyone have some thoughts on this one?

 

[lambskin]

Looks like an ammy but I am no expert or professional. Pretty stone.

 

[Sunseeker888]

I also forgot to mention, it is engraved with the initials "FCM"

 

[chrono]

Probably amethyst.

 

[Arcadian]

From the image, it looks like amethyst. but not sure, it could well be synthetic too, you never know until its been checked out.

 

[arkieb1]

My guess would be ammy, or something synthetic, maybe a purple topaz or purple garnet as a long shot but most likely to be amethyst or a man made stone.