Desiccant storage
Keeping meteorites in sealed containers with a moisture-absorbing material, such as silica gel, to stop them rusting.
A desiccant is a substance that soaks up water vapour from the air. The most familiar is silica gel, the little beads in sachets packed with new shoes. Desiccant storage means putting meteorites in an airtight box or jar along with a desiccant, so the air inside stays very dry.
This matters because many meteorites contain iron-nickel metal and iron sulfide, which react with moisture and oxygen. Iron meteorites and metal-rich stones can rust, and some suffer from a chloride mineral called lawrencite that attracts water, causing flakes and cracks to break away. Iron meteorites from Campo del Cielo in Argentina, for example, are well known for rusting if they are left in damp air. Carbonaceous chondrites, which contain delicate water-bearing minerals, also benefit from dry, stable storage.
You can check whether storage is working by using indicating silica gel, which changes colour as it becomes saturated. It can then be dried out in a warm oven and reused, a job for an adult. Keep specimens out of humid rooms such as kitchens and bathrooms, and avoid touching fresh metal surfaces with bare hands. Never eat silica gel, and keep sachets away from small children and pets.
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Level: Explorer Ages 10 and up