A particle presentation apparatus for presenting particles being conducted within a gaseous stream for instream spectroscopic elemental analysis includes a particle blending section for homogenizing the distribution particles of significantly different sizes received within a gaseous stream of randomly distributed particles; and a particle sampling section including a window that is adapted for passing a particle excitation beam, such as a laser beam, and photon emissions, and a conduit for conducting the homogenized stream of particles past the window so that a particle excitation beam passing through the window can pass into the stream of homogenized particles. The apparatus may be used in combination with a drilling machine, wherein the particle blending section is coupled to an outlet pipe of the drilling machine for receiving a said gaseous stream of randomly distributed particles that are expelled from a drill hole.