Spectroscope

Gem Identification

Definition

An optical instrument used to analyze the absorption of light by a gemstone, producing a spectrum with characteristic dark lines or bands that indicate the presence of specific elements.

Detailed Explanation

Gemstones absorb light at wavelengths determined by their chemistry. A natural ruby shows a strong chromium absorption doublet at 692–694 nm in the red, plus a broad absorption in the yellow-green. Synthetic rubies produced by flame fusion show the same chromium lines but may lack other features. Glass imitations show a broad, featureless absorption. The desk-model spectroscope (diffraction grating type) is standard in gemological labs, while fiber-optic spectrophotometers can record and compare spectra digitally, enabling more precise analysis and database matching.

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