bone, walrus, or ivory

[thart]

Dear List,                                                           
                                                                         
         I would appreciate any information that could be given me that 
would help identify the differences between walrus tusk keytops and ivory 
keytops.                                                                 
         I have read articles where reference was made to walrus tusk 
used as keytop material  but the exact differences were not mentioned.   
                                                                         
         I have a very strong interest in  turn-of-the-century and 
pre-1900's grand pianos. Especially the materials of their construction. 
                                                                         
         This question is very important to me as I am doing research on 
the subject.                                                             
         Thanks in advance for any information you might be able to 
share.                                                                   
         Sincerely,                                                      
                                                                         
         Michael W. Hart                                                 
                                                                         
         thart@tcnet.net                                                 
         (606) 528-8760  (Collect)