Product Overview

The Refractive Index Meter (RI Meter), also known as a gemstone refractometer, is a gemological testing instrument designed to help identify gemstones by measuring their refractive index (RI). It is useful for gemologists, gemstone dealers, jewelry professionals, and gemology students.

This instrument helps distinguish gemstones such as sapphires, rubies, emeralds, garnets, and other transparent or translucent gemstones. The package includes a complimentary demonstration liquid for educational purposes.

Sample product specifications

Feature

Details

Product Name

Gemstone Refractive Index Meter

Model

GEM-RI-2026

Brand

GemTest Instruments (fictional)

Measurement Range

1.30–1.81 (illustrative)

Display Type

Optical scale

Application

Gemstone identification

Package

RI Meter, protective case, demo liquid

Warranty

12 months (sample only)

Intended Users

Gemologists, students, jewelers

How to Use the RI Meter

  1. Prepare the instrument: Place the refractometer on a stable, clean surface.
  2. Prepare the gemstone: Ensure the gemstone has a clean, flat, polished surface.
  3. Measure the gemstone: A trained operator uses suitable contact liquid according to the instrument's instructions and chemical safety documentation.
  4. Observe the reading: The refractive index appears on the optical scale.
  5. Identify the gemstone: Compare the recorded value with established gemstone RI reference charts.

General measurement principles are described by the International Gem Society.

Example gemstone RI values

Gemstone

Approximate RI

Ruby

1.762–1.770

Sapphire

1.762–1.770

Emerald

1.565–1.602

Amethyst

1.544–1.553

Spinel

1.712–1.736