Liquid to to match the refractive index of a specific glass.

I'm trying to match the refractive index of a specific glass. What should I use?

Any of our Standard Series Liquids can be used to match the refractive index of nearly all glasses and plastics. For larger quantities, or a more exact refractive index match to your material, you should use one of our custom blended Immersion or Laser Liquids. We regularly manufacture liquids to match the refractive index of BK7, SF10, BaK, Fused Silica, PMMA, Polycarbonate, Polystyrene, and other glasses and plastics. Because many of our liquids are custom blended, we can ( most likely ) match the refractive index of your material at any wavelength and temperature. Please contact our technical services department to help determine which liquid is the best for your application.

http://www.cargille.com/faq.shtml