Small Pre-Columbian Shell Beads (by the piece)

We have about 20 of these lovely Pre-Columbian shell beads or appliqués.  They are most likely mother of pearl, with the slightest hint of a beautiful iridescence.  We think quite old, but we are not entirely sure.  Price is per bead. 

These tiny items measure approximately 20 mm in length by 12 mm in width.  It's important to note that these "beads" are very thin -- less than 2 mm thick -- and some are a little fragile.  Four representative beads measures 2.5 grams.  

I admit, I broke one while photographing, and there was a thin white residue coming off a couple of the beads).  For the right project (or simply to collect), however, I think they would be amazing, so long as they are not weight-bearing.      

As you can see, many are slightly damaged, missing one of the little appendages that stick out, but most are in surprisingly good condition.