How long can crystals be stored for?
Depending on the Type of Crystal and Storage Conditions, Quartz Crystals have an indefinite shelf life.
Storage conditions for all crystals are the chief component in maintaining the crystal integrity and maximizing shelf life. The crystals should be stored in their original package to prevent physical damage, dust accumulation, and contamination from foreign substances present in the laboratory or production environment. Be sure to only handle the crystals with tweezers and/or powder-free gloved hands.
Moreover, all crystals—regardless of type—should be stored in a temperature range of 50-80*F and a maximum of 30-40% relative humidity. That is to say, the warehouse or stockroom should be dry and climate controlled if possible.
Gold and alloy crystals are for inert and require no special care for long term storage. These crystals can last many years in proper storage.
Silver crystals, are prone to oxidation if stored in normal atmospheric conditions. Oxidation might become present over 1-2 years of normal storage. The only way to prevent oxidation with silver crystals is to store them in a nitrogen-rich environment such as a properly configured dessicator. Phillip Technologies stores silver crystals in nitrogen in an effort to maximize their shelf life before and after delivery to the customer.