Description

Although this is undoubtedly an industrial-grade product, I have been unable to find any equivalent microscope. It seems to be either a one-of-a-kind device created as a special order or a prototype developed for a specific use, which ultimately was not produced due to its niche application. Nevertheless, this microscope is the most compact petrographic pocket microscope I know of, offering all the necessary features for examining petrographic thin sections. It includes a slot for integrating wavelength plates (λ, 1/4λ, and quartz wedge, not included), as well as options for measuring extinction angles and birefringence. It can be held by a handle that screws out, and the lighting is achieved by positioning it in front of a light source.

I received a note from an expert in the history of petrographic microscopes, stating that it is, in fact, a handheld polariscope intended for student use to pass around in class.  They are quite rare; he hasn’t seen one in many years (aside from the example listed here). He believes the eyepieces are replacements, but I disagree, as they fit perfectly in both diameter and focal length. Otherwise, the instrument is in good overall condition. His example, which appears to be from a later period, is signed by J. Swift (London) and is constructed similarly, providing a fairly decent image of a standard thin section.