Determing expediency of feeble buttons? I have a large amount of buttons that be purchased at an...

I have a large amount of buttons that be purchased at an auction. some are obviously from the 70s, a few 80s, but some appear to be quite old-fashioned. There are gorgeous mother of pearl ones as small as 1/4" to as big as 1 1/2"!!, and lots of other various materials. There is a whole baggie of tiny little ones (less later 1/4" larger then 1/8" that are like a black metal, beside a tiny metal shank. Some even appear to be soapstone! I'm wondering if there is a way to detail how old they may be? And at what point do I say "hey, this might be advisable, and I shouldn't attach it to some random craft." I know some old buttons can trade for quite a bit of money individually. I don't want to have one and on a whim glue it to something! lol

Also, any ideas how to soundly clean them? With such a huge variety of materials I am second guessing ever opinion I have!
Need a picture of a house?
Answers:    http://vintagebuttons.net/educational.ht...

http://www.geocities.com/janlcc/index.ht...

Hopefully one of these sites can get you started on finding out roughly your buttons.