Oftentimes, physical property tests are not sufficient to establish the entire composition of a mineral and more reliable measures become necessary. Raman spectroscopy is an analytical technique used by scientists to examine the manner in which light, in the form of a laser, interacts with a sample substance, be it liquid, solid, or gaseous Instruments 2012. The technique relies upon the idea that the monochromatic UV - NIR (near infrared) wavelength light from the laser is made up of photons that change their behavior at the point of interaction with the sample Instruments 2012. Some of these photons are absorbed by that sample, and reemitted at a different frequency than that of the original monochromatic light Instruments 2012. This shift in frequency is known as the Raman effect Instruments 2012. The reemitted light is collected through a lens and after undergoing an interference filter, the Raman spectrum of the sample can be displayed Instruments 2012.  This spectrum can oftentimes offer, through analysis, substantially useful and important information about the chemical makeup of the sample. Raman spectra are often critical for determining an unknown substance as the collected data can be run against a database of known spectra in order to determine a match in terms of what the chemical makeup is and the relative amounts of those individual parts of the makeup are.