About Refractive Index Liquids

Cargille’s Expertise

Cargille Refractive Index Liquids have become standard items in many laboratories as their applications have expanded from routine mineralogical identifications and quality control. New and broader uses in many more fields such as chemicals, engineering, medical, forensic, optics, and instrumentation are continuously discovered. Many special requirements for specific applications have created a need for more technical data, new formulations, extended ranges, smaller increments and higher degrees of precision.

Since 1942, Cargille Laboratories has been filling this growing need. And today, the largest and most comprehensive assemblage of refractive index liquids – over 250 stocked items – is available for science, industry, medicine, and education. For specialized and unusual applications, many more can be formulated and others are routinely researched in anticipation of new needs.

CFCs in Refractive Index Liquids

Chlorofluorocarbon (CFC) components used in some Cargille optical liquids have physical properties that are harmless to the ozone layer, unlike those found in refrigerant gases, propellants, and solvents, which are destructive. The components used by Cargille Laboratories have vapor densities ten times that of air, are relatively nonvolatile, and have boiling points at least 100°C higher than the highest-boiling CFC of those listed for removal from commercial use by the Montreal Protocol.


Cargille Refractive Index Liquids have a broad range of applications in diversified fields. The following table briefly illustrates some of the typical areas of use.

TYPICAL APPLICATIONS: Identify minerals, ores, chemicals, specimen fragments, plastics, gems, translucent or transparent solids by microscopic immersion techniques.

TYPICAL APPLICATIONS: Temporarily mount specimens in various index media for matching or contrasting index combinations.

Mount specimens and thin sections in a stable, viscous, nondrying index of refraction liquid to permit sample rotation by shifting cover glass for more comprehensive examination. (Cargille MeltMount)

TYPICAL APPLICATIONS: Microscopically study solids by dispersion staining, focal masking, and double variation refractometry techniques with high dispersion liquids.

TYPICAL APPLICATIONS: Calibrate refractometers and other optical instruments.

TYPICAL APPLICATIONS: Instruct and exhibit principles and applications of refraction.

TYPICAL APPLICATIONS: Determine refractive index of specimens by referral to calibration curves relating wave length to index of refraction.

TYPICAL APPLICATIONS: Examine stress and strain effects of transparent or translucent items; molded, formed, curved or intrinsically shaped parts by polariscopic immersion technique. (Cargille Immersion Liquids)

TYPICAL APPLICATIONS: Identify salts precipitated from body fluids and measure relative amounts of sodium and potassium chloride for indicating toxemia.

TYPICAL APPLICATIONS: Couple optical elements with liquids formulated for refractive index and viscosity.

TYPICAL APPLICATIONS: Obtain unique optical properties of hollow lenses by filling with index of refraction liquids.

TYPICAL APPLICATIONS: Examine and preserve cathode coating without stripping or re-immersion by utilizing oils matching index of crystals.

TYPICAL APPLICATIONS: Identify particles and particulates from air or water.

TYPICAL APPLICATIONS: Photograph flow patterns by filling test system with refractive index liquids having suspended “beads”.