Shell arrowheads are an interesting topic. I know it can be done but that is about it. As for hooks and spears, I have seen descriptions of them for the Pacific coast tribes . In William Henry Holmes book art in shell of the ancient Americans, he states that " the use of shell in the manufacture of fishing implements seems to have been almost unknown among the tribes of the Atlantic coast". Keep in mind this was published in 1923. Archeologists may have made new discoveries since then.
Part of this may have to do with manufacture time. The work involved with shaping shell makes me think that if I can get the same function for a bull shark tooth, or an arrow head -- well I would. Less time is invested. I know time is not always the issue. Look at how much time goes into making a stone bannerstone, an igneous ax or a black drink cup. They are time expensive items by comparison to other crafts. However, the absence of shell spears and arrowheads makes me think effort was the issue here.
Theoretically, I would say shell would make a solid harpoon point. The stuff is really hard to work because it is tough. I have worked some bone, but not a lot. It would be interesting to see which one would be more durable bone or shell harpoon blades.
But I am still learning. Notice all the weasel words like " I think," and "I would say". I will keep digging. Fun stuff to learn about.
