Abstract: Diamonds and other precious stones for investment purposes are stored in individual packages which cannot be opened without destruction and which contain, in addition to the precious stone, preferably exposed through a transparent window, various data carriers or information traces which form part of the sealed package. The package can also include optically discernible information as well as information stored in an electronic form, e.g. in a programmable read-only memory (PROM) which can be read upon insertion of the package into an appropriate monitoring device so that information stored in the PROM can be compared with other information, e.g. from a central data bank or information keyed into the device, to determine validity, value or characteristics of the gem.