For all who are curious about glass disease

Glass Disease:

A durability defect of glass, leading to disintegration, due to a wrong balance of oxides and is unusually high in alkali or low in lime. It is characterized by surface moisture and dulling, and crizzling.

More info can be found at:

http://216.239.37.100/search?q=cache:qUzEeTvFeB8C:nautarch.tamu.edu/class/anth605/File5.htm+%22Glass+Disease%22&hl=en&ie=UTF-8

Basically, glass disease is a breakdown of glass. It forms alkaline substances and leaves a hazy, powdery residue. If anything, it should not cause concern about the condition of shell material. Remember, Bynesian Decay (Byne's Disease) is due to acidic deteriorization of shells (CaCO3). Glass disease results in alkaline materials and should not harm the shell. I believe soda-lime glass (flint glass) is most at risk and the more expensive borosilicate glass is less at risk. You can determine which glass you have with UV light. Soda-lime glass fluoresces a yellow-green, borosilicate glass does not. Paul Callomon, from the Academy of natural sciences (philadelphia) presented a nice talk on this at the American malacological Society Meeting this year. I will check my notes to see if I left any details out. Hope this helps. Regards, Charlie ****************************************************************************** Charlie Sturm, Jr Research Associate - Section of Mollusks Carnegie Museum of Natural History Pittsburgh, PA, USA

Assistant Professor - Family Medicine

csturmjr@pitt.edu