Old house owners:

Perhaps you will get a chill out of this find!

http://www.ohio.com/dist/nf/004646.htm

Steve Stokowski
Stone Products Consultants
Building Products Microscopy
10 Clark St., Ste. A
Ashland, Mass. 01721-2145
508-881-6364 (ph. & fax)
http://members.aol.com/crushstone/petro.htm