Minerals and Inorganics
Raman Imaging and Microscopy Mineral Applications
Analysis and evaluation example of diamond abrasive surface
For an optimal performance, diamond abrasives must meet several criteria. Among these is a uniform distribution as well as a high crystallinity of the diamonds on the surface. Low crystallinity would lead to reduced hardness, negatively affecting the performance and durability of the abrasive. In this context a diamond abrasive was analyzed using the RAMANtouch microscope.
A bright field microscope image alongside a Raman image is shown below, illustrating the surface of a diamond abrasive. In the conventional microscopy image, diamonds appear in black and dark grey tones. However, Raman imaging reveals the presence of two distinct diamond types, shown in red and green.
Analysis of the diamond spectra suggests that one type (green spectrum) exhibits lower crystallinity compared to the other (red spectrum). Further examination of the Raman image revealed that diamonds occupy approximately 68.94% of the overall area within the abrasive. Notably, the majority, almost 61%, consists of diamonds characterized by high crystallinity (red).
Asbestos detection and analysis
Asbestos is a collective term for various naturally occurring, fibrous crystalline silicate minerals such as actinolite and chrysotile. In cases where the fiber length exceeds a size of 5 µm, a diameter of 3 µm and a length-diameter ratio of 3:1 the fibers can reach the pulmonary alveolus causing considerable harm. Therefore, it is important to determine the composition and size of supposed asbestos fibers.
The challenge? The small size of the fibers!
By providing high-resolution, the RAMANtouch is able to analyze and depict the smallest of fibers down to the nanometer range. A sample that was suspected to contain asbestos was thus measured. The spectrum gathered of the sample was compared with a spectral library and revealed that the sample is made of chrysotile. The Raman image of the sample shows minute chrysotile with the typical Asbestos needle-like shape. With the parameters mentioned earlier, the depicted chrysotile fibers did not exceed the 3:1 ratio and were not deemed potentially harmful.
