The Indissoluble Bond between Watch and Sapphire

Materials of table mirror of watch frequently include glass, sapphire and plexiglass. Sapphire is a very important identification to judge whether the watch is vintage or not. Then what is sapphire table mirror?Sapphire refers to all the corundum gemstone expect of ruby, it main ingredient is the alumina (AI203). Blue sapphire was formed due to the mix of a small amount of titanium (Ti) and iron (Fe) elements. Due to the high hardness of sapphire, watch made with this material is of better shock resistance, sealability and strength than made with other materials, which is an important assurance for the quality of top watch.Nowadays sapphire mirror installed on the watch is actually aluminum oxide which has removed other impurities. The synthetic sapphire has no difference from natural crystal from the chemical point of view; it is colorless due to there is no adding of other elements. Pure alumina is made into original synthetic sapphire at high temperatures, and then being cut into discs and polished into table mirror. Because of the high consumption of processing tools, the cost of sapphire table mirror is relatively high. The synthetic sapphire technology was invented in the 19th century and applied to watch in the 1960s, top watch brands are generally take advantage of sapphire table mirror when producing watches.Then what’s the advantage of the table mirror?Firstly, it will not be scratched. High hardness of sapphire determined it is the inevitable selection of making vintage watches. However, once it is broken, the maintenance costs will be very high because the “disc” is so fragile that watchmaker must examine carefully to ensure there is no sapphire fragrances left in the movement before replacement of lenses. In addition, it is a “fingerprint collector”, thus regular cleaning should be exerted to keep the mirror bright and seamless. Both natural and synthetic sapphires are the hardest objects in nature, for there aren’t any other substances that have their hardness reached Mohs 9 expect diamond. While pay attention here, other substances mean in nature, not the earth. Hardness of some man-made silicon-carbon can reach level 9 and can scratch sapphire as well. Many construction and decoration materials would take advantage of silicon-carbon compounds as well, such as artificial stone, thus when friction between sapphire and these materials, scratches might occur.Can sapphire crystal glass be replaced with mirror?The answer is no, for thickness of cases are not the same. Table mirror of sapphire is thicker than plexiglass under normal circumstances. You might find sapphire table mirror of appropriate size, but the water resistance of the watch might be destroyed, in addition, the results of doing so might be that many manufacturer refuse to provide maintenance to the watch.How to identify sapphire table mirror?1. BreathingBreathing on the surface, if the mist disappear rapidly it is sapphire crystal glass. Generally speaking, the moment when you take the watch away from your mouth fogs would disappear at once.2. Tapping Gently tap the surface so that you can distinguish “true or false” by sound. If the sound is dull, it is “true”; the sound is crisp once it is general crystal or glass. Well, keeps it in mind, tapping gently to avoid the mirror being cracked.3. Dripping When conditions allow, you can drip a droplet on the surface and then ruffle it, if the water droplet will not come apart and slide slowly, it must be sapphire crystal.How to identify three materials of table mirror?Firstly, you can gently tap the mirror with fingers and listen carefully to the sound. Sound of acrylic material is plastic-like and glass is relatively thick. Then judging from the weights, material of acrylic is the lightest, sapphire is the hardest. Due good effect of thermal conductivity of the sapphire, there will be a cold feeling when you touch the surface. Because the surface of sapphire mirror is far smoother than the other two, water droplets on the surface is not that easy to spread, while on other materials, drops would scatter into one at once.