Hi, here are some of my buttons made from abalone shells that I caught in the Santa Barbara Channel back in the day when I was underwater a lot. I have crucifixes, hearts, and other shapes too. I can post more images of those items later.
Some phone pics of the crucifixes, buttons (~1"), and a couple of unfinished items on the lower left of that photo. The crucifixes are thick, using heavy shells found near The Hollister Ranch and along that coast. I've saved these shells from the 80s and 90s before the fishing closure.
The pendant on the bottom right is made from pink abalone shell and I didn't cut nor polish the face leaving the natural finish.
I'll post some more images when I can, and I'm going camping for a few weeks so be patient if your interested, and I'll get back to you when I can. The heavy pieces of abalone are rare, abalone like this is no longer available.