A magnifying glass is an essential tool for those who are fond of jewelry and minerals. In this article we will tell you how to choose a magnifying glass!
But first, a little history
It is believed that the first lenses were made of rock crystal as early as the time of Troy (2500 BC). The ancient Greeks probably noticed the magnifying effect on a clear glass vessel, or on a convex drop of water. But they began to use them to enlarge the image far from immediately. Man figured this out only in the 13th century. Lenses were inserted into pince-nez, monocles and telescopes. And in the 17th century, Galileo created the first microscope – the prototype of the modern microscope.
Of course, a magnifying glass is much simpler than a microscope. For example, a magnifying glass for reading or looking at small objects is a convex lens with a handle. It magnifies by a factor of 2 or 3. Magnifiers of this magnification are not suitable for looking at a sample, a chip on a stone, or inclusions. Though they are often beautifully designed with carved handles and graceful frames. Sometimes there are magnifying glasses in the form of pendants on a chain. They are of little use for our purposes. It turns out that more diameter of the lens means less magnification.
To study jewelry and stones, a magnifying glass with tenfold magnification is quite good. It has 2 cm diameter of the lens. Its maximum distance to the object is 1 to 2 cm. It is necessary to bring the magnifying glass tightly to the eye and hold the object very close. We keep the other eye open. At first it is unusual, but with time it is easy to adapt. Why? So as not to strain the eye and not to create wrinkles around the closed eye.
The most important thing in a magnifier is the lens. A 10x magnifier usually has 2-3 lenses together. Glass lenses are better than plastic lenses. Magnifiers give some color distortion and blurring, but you can’t do without them.
They make magnifiers with backlighting. But they have two disadvantages: the bulb is short-lived and shows the object only in reflected light. If you want to look at a stone, the side illumination or the through illumination will do you better.
Pay attention to the body of the magnifier. It should be matte black, so as not to give false glare and reflections.