Blade Stamp question

[Ian.Fleming]

Hey guys,
I came across a photo of this blade:

I am curious if any of you might know what the marking on the bottom of the blade might symbolize or mean?

 

[Ian.Fleming]

The image was from this website: http://www.ksky.ne.jp/~sumie99/steel.html

 

[shirogane]

They are not stamps, they are carved.

The closer one is a stylized sacred jewel. The one further down the blade is called "bonji" and is a sanscrit character.