Shimadzu Kalnew Gem Refractometer 1960s~70s

Shimadzu Kalnew Gem Refractometer

Japan, c. 1960s–1970s (estimated)

Shimadzu Kalnew ≈ “Shimadzu (島津製作所) New Calibration (Optical) Series".  Manufactured by Shimadzu Corporation — an early leader in optical and analytical instrumentation — the Kalnew series was designed to provide reliable refractive-index measurements for gemologists, appraisers, and educational institutions.

Built in a rigid, precision-machined housing, the instrument features a high-quality optical glass hemicylinder, an internal illumination system, and a fixed-scale readout visible through the eyepiece. Its sturdy construction and stable optical alignment made it a trusted tool at a time when gem testing laboratories in Japan and abroad were expanding rapidly.

This object belongs to the museum archives. No unit is available for purchase at this time.