Please help to identify this mark on a Japanese (?) pendant

[Zenta]

Hi, all - first-time poster here!
I would appreciate any help you can give me - I would love to know how old this pendant is and where it might be from. Thanks!

http://sv1.letmehost.com/img.php?file=s ... _Front.JPG" onclick="window.open(this.href);return false;

http://sv1.letmehost.com/img.php?file=s ... _Marks.JPG" onclick="window.open(this.href);return false;