ABSTRACT
The optical microscope (OM) is much older than other characterization instruments and uses the visible or near visible portion of the electromagnetic spectrum to observe objects of interest. OMs are the cheapest "modern" instrument and take up little physical space. They are capable of handling almost every type of sample and can easily provide high magnifications up to 1400X. Even though it is not quite certain who invented the microscope, its origin can be traced in the Netherlands between 1590 and 1610 and the first well-known microscopists were A. van Leeuwenhoek and R. Hooke. Since the mid-1800s, the OM has been used to view virtually all materials, regardless of their nature or origin. In 1882, H. Le Chatelier published the results of his work on cement chemistry, in which he identified various constituents of Portland cement clinker using microscopic examination in polarized light [8.1].
