Can you help identify this piece?

Hello,
Thank you for having me here.
I'm trying to find out information on this rock shape vase I got at an estate sale auction.
There wasn't any info in the description and the person at the pick up point could tell me anything about either.

It's unglazed looks like high-fired- wood fired? Stoneware.
Can you help?

[url=https://servimg.com/view/20075554/1][img]https://i.servimg.com/u/f12/20/07/55/54/img_2010.jpg

It looks like raku, which is low fired and then placed in a pile of paper while still red hot and is coated by the carbon from the burning paper. It might have had a copper matte coating but that will have oxidised long ago.
Dated 1979, and possibly signed Shulman?  
worth trying The Marks Project in the hopes the potter is listed

Thank you so much Naomi!!!!
How do I check the Marks Project?
And one more question regarding this vase?
If it's not a listed Potter how can you determine a value to the piece? What criteria to I go by?
Thank you so much!!!!!

https://www.themarksproject.org/

Until it's Identified it's basically worth what you paid for it.

Thank you!