The crystals we provide are consumables and, like any other product, show wear when used for experiments. Over time the crystallinity tends to degrade and the crystal tends to collect impurities from the experiments it is used for or the system it is used in. When exposed to high enough temperatures the dimensions will slowly go out of spec, and the local alignment will alter as a result of forces exerted on the crystal. The degradation of a crystal sets in immediately after it is first clamped or mounted in an experimental setup and prepared. From the many years of experience that we have in crystal preparation it is fairly trivial to tell apart the effects of regular and correct use of the crystal on the one hand, and a faulty product that we may have inadvertently provided on the other hand. This also holds for defects and damage caused by misguided use and other forms of torture and maltreatment that crystals can be put through. We will replace them if we are at fault, and will work with our customers to resolve the problems that are experienced in other cases.