There is a difference in the glass and their respective hardness due to any process that would change it, of course the harder the material, in this case glass, the higher the pitch through the friction applied to it. Regular glass, if there really is such a thing, is created through the heating, melting and spreading of the granules of sand and when mixed with hardeners will cause sound quality to change as more hardeners are added. This is true throughout the entire piece, Bronzed glass, is a process where a chemical change has taken place on the outer layer of the glass, once removed it reveals the original glass below it and according to what materials were added to harden the glass would dictate the resonation qualities of that glass, what it does as "bronzed" glass it keeps the movement of the glass under friction tighter, resulting in high pitch with rasp follow up. Crystal is glass with lead, actually softer then a regular piece of glass and the process used to make it is more complicated and the general appearance is clearer then the regular glass, the surface of crystal is easier to condition, therefore the friction rate is better, the sound generally is lower in pitch then regular glass. Working a call when wet would require a striker designed to do so, glass can be worked when wet, but it takes a striker with water proof material on the tip, I believe there is a fellow here on the site who makes them and has a great track record with them. You should do a search for them if you are intending on hunting in wet conditions. I hope this was helpful, pappy