Beryl is a mineral that may be difficult to distinguish from quartz by casual field inspection. The easily recognized green color and hexagonal crystal form of coarse-grained beryl are by no means universal, even in beryl from pegmatitic deposits. If it occurred as a fine-grained accessory mineral in an igneous rock, it would almost certainly escape detection unless samples were submitted for petrographic or chemical analysis. There may be substantial deposits of some beryllium mineral, other than beryl, that has been overlooked because that mineral also closely resembles the common rock-forming minerals.
The original discovery of the neutron by Chadwick in 1932 resulted from experiments with another nuclear reaction, induced by bombarding beryllium with alpha particles in which the products are carbon-12 and neutrons. The equation for this reaction is as follows:
Experimental Work: The experimental work was carried out by bombarding samples of beryl and of metallic beryllium with alpha particles from a polonium-plated silver foil.
The method of preparing the mineral sample was dictated by the need to get a large amount of the sample at a uniform distance from the polonium source. Therefore the mineral sample, usually a piece of beryl several