Identifier Of Top Watch Sapphire Mirror

How to determine whether a watch is classified as a top brand, you can see whether it uses a sapphire mirror. The hardness of sapphire is high. Watches made with it have shock resistance, sealability and The strength is higher than other materials, which is also an important factor in the quality assurance of top watches.
The Nuremberg Egg invented by Nürnberger Ei
    Glass appeared thousands of years before the appearance of clocks, but the earliest clocks had no glass cover. According to the literature, the Egyptians four thousand years ago had already understood the technology of glass firing and started to use glass as a container. Pocket watches, however, did not appear until the 16th century.
    Pocket watches were invented by a German named Nürnberger Ei. There has been considerable controversy about his pedigree. Some people think he is a Germanic, because he spent eight years making a clock for the then French king. However, some people think that he is a Jew, because the clock he designed will have some time lag every year, the King of France has to give him some gold coins every year, let him be responsible for the maintenance and proofreading of this clock. The pocket watch he designed was the size of a goose egg, called the ‘Nuremberg Egg’. It could not be placed in the shirt pocket, but could only be hung around the king’s neck.
    At the time, this ‘egg’ had no glass cover. It is not that Nürnberger Ei did not expect it, but that the glass produced at the time was not colorless and transparent. The glass in that meeting contained iron compounds, and people didn’t know how to remove the iron element from the glass. Because the color of the iron compound was green, the color of the glass at that time was the same as the current beer bottle. Putting this color of glass on a pocket watch can only get one result, that is, everyone can’t see where the pointer is now. Therefore, instead of using glass to make a protective cover for Nürnberger Ei, he added a ‘golden bell cover’ to this pocket watch.
Jaeger-LeCoultre Master Grand Tradition Tourbillon Perpetual Calendar watch, 401 parts alone
How many parts are inside the watch?
    If it is a general, less complicated watch, there are dozens or even a hundred parts. If it is a multi-functional watch, it usually starts from two hundred parts and is not discounted. For example, Jaeger-LeCoultre’s Master Grand Tradition large-scale traditional watch series tourbillon perpetual calendar watch, the movement alone, there are 401 parts. In a watch, the weakest part is the fastest-moving balance wheel, and the balance journal in high-end watches is as thin as a hair. Such a fine balance wheel has to drive a wheel with a diameter of about 10 mm. For example, this is as dangerous as hanging a grinding disc on a small iron rod as thin as a pen. We all know that the surface area of ​​an object is proportional to the square of its size, that is, the smaller the size, the larger the surface area relative to the air, and the faster it is corroded. For a watch like this, if there is a seam to allow dust and water vapor to enter, rust will spread inside like a plague, and finally the watch will completely strike.
Therefore, sealed protection is definitely a big deal for watches.
Vacheron Constantin launches pocket watch named Patrimony Contemporaine
    Until a few hundred years later, with the birth of colorless transparent glass, glass appeared on the watch as a protective cover. Today’s pocket watches do not have practical value, but because of the retro atmosphere on them, they have become the oldest and the oldest, and have been favored by major brand manufacturers. For example, Vacheron Constantin launched the Patrimony Contemporaine just a few months ago. Pocket watch is very collectible.
Rolex Oyster Perpetual Explorer-type mirror: sapphire crystal
However, people soon discovered that although glass can play a good role in blocking water vapor and dust, it also has its own shortcomings: fragile, easy to absorb fat, and too expensive.
Fragile, so that many pocket watches have a lifespan of less than one year; easy to absorb fat, make you want to repeatedly wipe with a piece of handkerchief on it, and because the hardness of the glass is low, you will easily make the pocket watch The mirror surface became misty. Coupled with the high price, before the advent of plexiglass, ordinary glass was still widely used as the main material of table mirrors.