Equipment and process for three-dimensional measurement of size and shape and for compositional analysis of mineral and rock particles and the like objects. A mixture of particles or objects of same or different sizes of minerals or rocks or the like are fed individually and automatically onto a conveyor belt for three-dimensional machine vision measurements using laser and two cameras and subsequently for spectroscopic measurements using visible and infrared light and are then collected at the end of the conveyor. Computer software is used to perform the measurement automatically and to calculate size, form, roundness, and preferably petrographic composition and other characteristics or properties of each individual object and the statistical distribution of relevant properties, either according to built-in measurement processes or user specific methods.