I'm definitely not an expert on buttons, or anything for that matter, however I do believe these are from
some type of shell. I would also think most are from the early part of the 20th century. I was born and raised on
the very northern CA coast, and went rock picking for abalone for the first half of my life - and many of these
buttons remind me of their beautiful shells.
There are 2 and 4-hole buttons, some plain, some carved, some flat, some very thick, some shapes, some shank style, some that look to be whistlers and some more like a little ball. There are really large ones all the way to very small ones, like for baby clothes. (Or possibly doll clothes.) So many possibilities for using them, or just adding to a collection. When I counted these I came up with 597, but to play it safe - I'm listing as 550+.
These have not been cleaned nor threads removed. The ones stitched to the 3x5 cards were from the collection of buttons that I bought several years ago. The ones in the 9th photo in the lower left corner, that are threaded together, were from my MIL. (Since I'm the youngest in the family at 71, I'm quite sure those are from the 1950's or earlier!)
Please look closely at the photos as they really are the best descriptions. Thank you for looking at this listing, and **remember, I do combine purchases when possible to help lower the cost of shipping.
***Photos 1-13 are of the group that I laid out.
14-23 are of smaller buttons - needless to say - they're shown as a group.