The portable instrument, here referred to as a "berylometer," is a new geophysical tool for use by geologists in both exploration and examination of Be deposits. This is a scintillation counter which contains a phosphor having a high neutron to gamma ratio of detection and makes use of the Be 9 (gamma , n) Be 8 reaction. A gamma emitting source is carried in a shield on the bottom of the instrument which, when set upon any Be-bearing mineral or rock, causes the emission of neutrons from the Be which are immediately recognizable. Gamma rays are biased out, and neutrons only are counted. An automatic counting register records the neutron count, and since this is directly proportional to the Be content of a sample, a simple means of analysis is provided. The use of Be would expand rapidly if adequate reserves could be established and also if, with increased production, a lower cost could be attained. The discovery of nonpegmatitic deposits offers a better prospect for the development of substantial reserves in contrast to the generally small size of Be-bearing zones as found in pegmatites. Towards this end the berylometer provides a much-needed field instrument for all persons engaged in research for Be ore.