Butterfly brooch need help with marks please

[Marie620]

Hi . I have this butterfly brooch, that appears to be silver on the back and on the antenas. It has marks I have not seen before. The maker looks like TG with a strange symbol above the initals. It also has a Z with a circle around it and then the number 743. Can anyone tell me anything about these markings. The front is like abolone shell I think??

Thanks for your help.

Here is the links to my photos because my pictures are too big when I load them on here for some reason and I dont know how to change it.

http://i1157.photobucket.com/albums/p58 ... 012007.jpg" onclick="window.open(this.href);return false;

http://i1157.photobucket.com/albums/p58 ... 012004.jpg" onclick="window.open(this.href);return false;

[Marie620]

Also, Could it be Agate instead of Abolone shell?