DON'T: Use screws or hard objects to fixate a crystal
The most common kind of damage we observe in crystals that are offered for repolishing are large plastic deformations around places where the crystal was previously clamped or held in place. It is important to realize that crystal holders and components clamping crystals are subject to considerable temperature variations when a crystal is annealed. As a result thermal expansion occurs and this can cause something like a thick plate, screw head or other fixating element that is loosely holding the crystal in place at room temperature, to turn into a virtual death trap for the delicate single crystal when it is heated and expands. It is important to allow for thermal expansion of the crystal prefereably through leaf spring clamps, and where this effect cannot be prevented and a hard fixation is required, to design a crystal using one of several options that we offer like ledges or slits in a crystal to confine the deformation to a region of the crystal that is not under investigation.