An approach to verification and validation of algorithms that render transparent objects (media) is described. Rendering of transparent optically isotropic objects has been studied extensively. However, the papers devoted to optically anisotropic objects are few in number. The main goal of the present paper is to suggest a collaboration in creating and supporting an open database of tests. To prepare a real scene with a crystal specimen, to photograph it, and to describe the corresponding virtual scene is a complex problem. Obviously this is an almost impossible task for many devolopers of rendering algorithms. Well-known examples of translucent media are crystals. They are convenient for testing purposes as they have permanent solid shapes. Although the crystals are rendered by a recursive ray tracing algorithm, the tests considered in the paper can be applied to other algorithms.