【Essential Tool】The Refractive Index Fluid is a professional gemologist’s essential for accurately identifying the refractive index of gemstones, ensuring precise evaluation and appraisal every time. 【Broad Measuring Range】Designed for versatility, this Gemstone Refractometer Oil enables measurements between 1. 30 to 1. 80, making it suitable for a wide variety of gemstones, including and colored stones. 【Enhanced Inspection】This Refractometer Oil reduces on gem surfaces, allowing for clearer observation of inclusions and imperfections, thus facilitating more informed decisions when evaluating gems. 【High-Quality Packaging】Each Refractive Index Fluid Oil comes securely packed in a glass vial, ensuring safe transport and storage, while the 3ml solution provides ample quantity for numerous tests. 【Compatible & Convenient】This versatile fluid is easy to use with any refractometer, providing convenience for both professional gemologists and hobbyists who are passionate about gemstone testing.