What "style" is this very old MOP button?

[rosemary5325]

Hi there!  I'm finding a lot of this style of MOP button in a very, very old button collection from my great aunt.  Can anyone tell me the "style" of these buttons?  When would they have been made?  Do they date as early as Civil War?  The are fairly thick, 2 hole, with a donut like shape with a deep center.  The shell is very worn and has more of a matte finish now. Thanks for your help!!!

[quick_creations]

It is hard to say what kind of shell that is from the photos, but we generally know that buttons from freshwater mussel shells were used to make less elegant and more utilitarian buttons. During the mid and late 19th century, the discovery of abundant fresh-water mussels and clams in Midwestern rivers in the United States created a new industry. Around 60 button factories lined the Mississippi from Minnesota to Missouri. During the Civil War, a lot of buttons were made from bone.

[rosemary5325]

Thanks for your response,and a little bit of history - I appreciate it.  Would there be a particular name of this style ie. shape?  How would you call it, beside 'mother of pearl button'.....?  So many buttons have names based on their shape, etc.  Bubble, picture, drum, etc.  Any thoughts?