{"product_id":"gia-analyzing-gem-refractometer-c-1949","title":"GIA Analyzing Gem Refractometer (c. 1949)","description":"\u003cp\u003eThe GIA Analyzing Gem Refractometer was one of the first commercially available gem refractometers to incorporate built-in polarization (at 0° \u0026amp; 90°) and diffused-illumination control through a mechanical filter wheel. Documented in Gems \u0026amp; Gemology (Spring 1949), this arrangement allowed the operator to modulate polarization, contrast, and illumination directly within the refractometer—significantly improving shadow-edge visibility and analytical flexibility, all within one of the most compact refractometer designs of its era.\u003c\/p\u003e\n\u003cp\u003eBuilt around a precision-ground truncated hemicylinder prism, the instrument was designed to provide stable and accurate critical-angle observations; at the same time, this refractometer maintained to be one of the smallest Refractometers ever made.\u003c\/p\u003e\n\u003cp\u003eThis is a museum archives and no unit is available for sale at this moment. \u003c\/p\u003e","brand":"Gems.studio","offers":[{"title":"Default Title","offer_id":51327281758528,"sku":null,"price":0.0,"currency_code":"CAD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0963\/0397\/2672\/files\/GIARefractometer3_6.gif?v=1767233919","url":"https:\/\/gems.studio\/products\/gia-analyzing-gem-refractometer-c-1949","provider":"Gems.studio","version":"1.0","type":"link"}