An important piece to almost any jeweler's skill and interest level is their gemstone or stone loupe. Pronounced looper, the jeweler's loupe is actually a compact hand lens and comes with one or more lenses to fit into your shirt pocket. Pronounced looper, the jeweler's loupe is often used by jewelers to get a much more detailed look at large rocks, stones, crystals, etc. For example, a jeweler may use a loupe to look deeply into a diamond stone to get an image of the refractive errors within the stone. Or, a jeweler might use the loupe to examine a bezel stone to find flaws or inclusions in the stone, which can then be removed and valued without damaging the stone. The loupe is also useful to have handy to inspect rings and necklaces for scratches and chips, as well as for identifying birthstones and other stones.
A jewelers loupe is used for much more than just gemstone or diamond inspections, however. In fact, it is often used to analyze jewelry and to examine the craftsmanship of the jewelry itself. This is most evident when a jeweler is testing a piece of dress or jewelry for quality. A jeweler will hold the loupe between his/her finger and thumb and lightly touch the stone or other jewelry to feel for quality or flaw. Often, this feedback is enough to ascertain that the piece is true of high quality and has not been treated with some sort of harmful chemical or procedure.
Diamonds and other precious stones are often the jeweler's loupe of choice. With a large variety of colors, shapes, sizes, and shapes, there is no better way to appreciate the qualities of a diamond than with a loupe. Diamonds can be analyzed with ease in this manner as well, besides being able to determine cut, color, and clarity. Many diamonds are even categorized according to carat weight. This information allows one to easily find the perfect diamond size for a particular piece of jewelry.
A jewelers loupe can be used to examine white gold, platinum, titanium, silver, and other precious and semi-precious metals. Many times, many semi-precious metals such as gold and silver can be observed with the naked eye but cannot be seen with the loupe. Some metals, such as titanium and platinum, have very strong colors, and they may be difficult to observe with the loupe. However, with a good jeweler's loupe and a good microscope, you can easily spot these colors, as well as distinguish them from a background.
The purpose of this instrument is multifold. It can be used in analyzing other gemstones and metals. This type of microscope is called a Microscopyuter, which can be found in many jewelers' loupe brands. This microscope is equipped with a bright arbor lens that magnifies objects up to 200 times. Besides providing magnification to objects, this microscope is also equipped with a focusing screen, so the owner can clearly see any flaws or minute scratches on the surface of the object they are trying to examine.
A jewelers loupe is available in many different sizes, depending on the diameter of the arbor lens. The most common size is a sixteenth-inch circumference. Some jewelers will sell their equipment in other sizes, based on the diameter of the lanyard they choose to attach to their microscope. For instance, a 6-inch lanyard will be different than a fifteen-inch lanyard. Some jewelers will even make a twenty-six-inch lanyard if the customer requests it.
When examining a jeweler loupe with its corrective glasses, check for accuracy and resolution. Also, note the degree of distortion in the images (either line or field) from the lanyard's focusing screen. The degree of distortion can greatly affect the quality of the image (especially if the field is not clear) and, therefore, the value of the microscope specimen.
Another feature that is important to note when looking at jewelers' loupes is the ability to adjust for aberrations or lens shifts. Most commonly, when an aberration or shift appears in the image, this indicates a defect in the specimen. To check for this, focus the loupe's lens toward the focus of the image and, while holding the loupe still, move it away from the focus. Aberrations and shifts are also often found in unaided vision (unlimited focus) pieces of jewelry, typically those made of black glass.