Interesting. When you say 'sea ivory' which species are you exactly referring to? I am not familiar with any marine ivory both displaying lamellar growth like that, and at the same time showing cracks along the axis shown above. Then again, there's probably a lot of sea mammals whose teeth I haven't seen myself - especially tropical ones.
I know that 'dots in a row' in ivory, is sometimes
associated with hippo tusks and their inner interstitial zone (TIZ), but the TIZ wouldn't take the direction shown in a cross section like the one above, unless your badik is very small. How long is the hilt btw?
From the picture above, I would still bet on blonde horn - unless you are sure that it is definitely tooth. In that case, it would be interesting to see a macro straight on the very end, as well as one perpendicular to the length of the hilt.
Sorry for the long ramble - nerding ivory is kindof what I do.
Sweet looking badik regardless!
All the best, - Thor