Laura, Please thank Tim. This is great info. Much appreciated. I owe a few beers. ][<en Laura Demko wrote: > Some limestones have significant iron-- ][<en Follett SOS Gab & Eti -- http://www.geocities.com/~orgrease Bullamanka-Pinheads website http://maelstrom.stjohns.edu/CGI/wa.exe?A0=bullamanka-pinheads