In my house it is a natural mixture of fluffy grey stuff, mouse turds and sawdust chips. Mr. Google says: "Rock wool is a naturally-occurring mineral fibre that looks like chopped white cottony material. (It may have originally been formed by wind blowing across streams of lava from erupting volcanoes.)" cp in bc (where two giant mountains of slag from the worlds largest copper smelter in the early 1900s was all turned into "Mineral Wool" during the 1960s.) ----- Original Message ----- From: "Ruth Barton" <[log in to unmask]> To: <[log in to unmask]> Sent: Friday, August 07, 2009 6:23 PM Subject: [BP] Rock wool insulation > -- > Can anyone tell me what "rock wool" insulation is composed of? Thanks, > Ruth > > > Ruth Barton > [log in to unmask] > Dummerston, VT > > -- > To terminate puerile preservation prattling among pals and the > uncoffee-ed, or to change your settings, go to: > <http://listserv.icors.org/archives/bullamanka-pinheads.html> > -- To terminate puerile preservation prattling among pals and the uncoffee-ed, or to change your settings, go to: <http://listserv.icors.org/archives/bullamanka-pinheads.html>