English: Closeup of the junction in a 2N140 germanium alloy junction transistor. This transistor was introduced by RCA in 1953 (in a TO140 package), and was their first high frequency transistor suitable for usage in the IF stage of an AM radio. The crystal is reflecting a blue light; it would naturally be silver colored. This picture is focus-stacked from 312 pictures, using a 10x microscope objective