Gemstones

Study of geological materials with Raman Spectroscopy
Natural rocks composing the Earth are complex. They consist of an aggregate of one or more minerals. Each mineral can be defined by its chemical composition and its crystalline structure and sometimes can also contain fluid inclusions. Geologists need a powerful characterization technique to get detailed information on the rock formation history. Raman spectroscopy is extremely information-rich (chemical identification, characterization of molecular structures, effects of bonding, environment and stress on a sample). With its non-destructive properties and high spatial resolution (< 1 μm), it is thus a tool of choice for geological studies.
Mining and Minerals Applications
Many particles encountered in mining are characterized by sieves. Recent advances make image analysis practical for samples with sizes larger than several microns in diameter. As particle size decreases, laser diffraction becomes the technique of choice.
Frac Sand and Proppants
Hydraulic fracturing is used in the oil and gas industry to increase the flow of oil and/or gas from a well. Proppants are pumped into the oil well with fracturing fluid to hold the fissures open. The proppant size, shape, and mechanical strength influences the integrity of the newly created fractures, and therefore the flow of oil and gas out of the well.
Ellipsometric Characterization of Doped and Undoped Crystalline Diamond Structures
Characterization of diamond layers by SE: crystalline undoped diamond layers on silicon substrate.
In this work, spectroscopic ellipsometry (SE) was successfully applied to characterize the optical properties and the thicknesses of doped and undoped diamond layers. The sensitivity of this technique enables the doped layer to be distinguished from the undoped one in a sample consisting of a stack of these two layers. Moreover, an interface between the two layers has been detected. This work and others reported previously show clearly that ellipsometry is the technique of choice for the characterization of optical and structural properties of layered materials thanks to its sensitivity and the wide range of information it provides.
Ellipsometric Characterization of Doped and Undoped Crystalline Diamond Structures
Characterization of diamond layers by SE: crystalline undoped diamond layers on silicon substrate.
In this work, spectroscopic ellipsometry (SE) was successfully applied to characterize the optical properties and the thicknesses of doped and undoped diamond layers. The sensitivity of this technique enables the doped layer to be distinguished from the undoped one in a sample consisting of a stack of these two layers. Moreover, an interface between the two layers has been detected. This work and others reported previously show clearly that ellipsometry is the technique of choice for the characterization of optical and structural properties of layered materials thanks to its sensitivity and the wide range of information it provides.