[ATM] Suspect glass question

[Starmutt at aol.com]

I recently picked up a 16.375" x 2.125 glass blank at a garage sale. It  says 
it is pyrex but lacks the normal yellowish cast of pyrex and the rounded  
smoothness of pyrex. It is whiteish and clear and looks more like a whitewater  
plate glass. The box says it came from Palomar optical. The price was low so  
even if it is a modified plate it was a deal. My question is this: Did Palomar  
market glass that was an import or did they fudge a bit on their description? 
 The stuff seems too brittle to be Pyrex so I am thinking about just using it 
as  a sub diameter tool on a 22" I am working on next.  Any input would be  
appreciated. Thanks in advance
 



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