Please help I/D

Hello everyone I purchased this necklace today at a local thrift store not knowing what it was but something about it I thought was interesting so for a dollar I thought what the heck it feels like stone but no idea if anyone can give me some info I would greatly appreciate it thanks .the largest bead is abou 3" and the small one is about 1.5" and marked sterling

 

sea urchin spines

 

Thank you hollyblue that is what they are I would have never figured that out that's why I come here when have questions. Wonderful people wonderful web site thanks again. Hollyblue

 

Yes indeed. The presence of such spines does not indicate an ethnic origin however; many hobbyist and bead sites sell them.
I bought a few several years ago for a project that didn't really work out....but they are interesting to work with, easy to drill, rather like a soft ceramic.