Steve. Sulphate minerals often seem to present stability problems with moisture; deliquescence, efflorescence etc. Similarly with sulphides with water and oxygen, eg pyrite decay. A few chlorides and carbonates as well, and minerals with high water of crystallisation.
In an ideal world storage in argon or nitrogen in tightly sealed containers might offer a solution.
In museum systematic collections, the sulphates often seem to present a sorry sight, especially if the show case is exposed to the warmth of direct sunlight during the day. One just has to try your best and accept casualties I guess.
Steve. Sulphate minerals often seem to present stability problems with moisture; deliquescence, efflorescence etc. Similarly with sulphides with water and oxygen, eg pyrite decay. A few chlorides and carbonates as well, and minerals with high water of crystallisation.
In an ideal world storage in argon or nitrogen in tightly sealed containers might offer a solution.
In museum systematic collections, the sulphates often seem to present a sorry sight, especially if the show case is exposed to the warmth of direct sunlight during the day. One just has to try your best and accept casualties I guess.