The watch glass is a vital component of any timepiece. When it comes to selecting the ideal material for this crucial component, sapphire glass stands out as the optimal choice. Not only does it enhance the watch's aesthetic appeal, but it also provides impeccable protection.

In this blog post, we will explore the various types of watch glasses, highlighting their distinguishing features and advantages. If you're looking to buy a new smartwatch, you might come across the term "sapphire glass". It's important to know what this means before you plan on buying it. Sapphire glass is a material used for the watch face that you might want to consider.


When crafting crystal watches, watchmakers opt for various materials to safeguard the dial. The three most commonly employed crystals are sapphire crystal, mineral crystal, Plexiglas (also called plastic), or acrylic crystal.

Watch Glass: Three Key Crafting Materials

  • Sapphire Glass: Sapphire Glass is primarily used in the luxury watch industry. Sapphire is a durable and scratch-resistant material, making it a popular choice. However, it is also the most expensive of the three types of crystals. Despite the cost, sapphire offers many advantages due to its resistance to scratches and shattering. Not only is it scratch-resistant, but it can also withstand cracks and breakage more effectively than glass or plastic.
  • Mineral Glass: Mineral Glass undergoes heat or chemical treatment to enhance its scratch resistance, although the level of improvement is not as high as that of sapphire.
  • Acrylic glass: Acrylic glass is commonly employed in cost-effective timepieces or for watch crystals possessing a considerable amount of curvature. However, it is susceptible to scratches and can impart a substandard impression. 

Decoding Watch Glasses: Understanding the Differences

When it comes to the durability of your watch, the glass it's made of plays a significant role. It's important to understand the differences between the three types of watch glass available - acrylic glass, mineral glass, and sapphire crystal. Acrylic glass is a plastic material that's easily scratched but can be polished multiple times. It's also impact-resistant and inexpensive, making it a good option for children's watches. 

Mineral glass, on the other hand, is made of tempered glass that's heat-hardened to increase its hardness and reduce the likelihood of breaking or scratching. Lastly, sapphire crystal is a synthetic material made from pure aluminum oxide that's crystallized at high temperatures. It's extremely hard and transparent, with the same hardness as natural sapphire. 

Knowing the differences between these materials can help you make an informed decision when choosing a watch.

Benefits of Sapphire Glass: Unmatched Clarity and Durability

Sapphire glass, also referred to as "synthetic sapphire" or "sapphire crystal," is a material that is highly regarded for its exceptional clarity and remarkable resilience. Unlike natural sapphires utilized in jewelry-making, this specialized material is produced through the synthesis of pure aluminum oxide with the utmost precision, resulting in an immaculate, colorless structure. The manufacturing process involves intricate techniques that meticulously eradicate any natural impurities, guaranteeing unparalleled transparency that enables light to pass through with minimal distortion, providing an unrivaled viewing experience.

To improve the clarity of sapphire glass, an antireflective surface coating can be added. This thin layer eliminates reflections and ensures a clear and transparent view of the watch face. This technique is often used in high-quality eyeglasses and camera lenses to produce the sharpest possible images. The application of this coating can significantly enhance the appearance and quality of the watch.

Anti-reflective coating

Anti-reflective coating, also known as AR coating, is a very thin layer of material that is applied to optical components like eyeglasses, camera lenses, watch glass, and computer screens. This coating helps reduce the amount of light that reflects off the surface of the component, making it easier to see and reducing glare. Sometimes, people mistake some of the lines and marks on a sapphire crystal for scratches. 

However, these marks are usually just scratches on the anti-reflective (AR) coating or a sign that the coating is starting to wear away because of frequent use. To avoid these issues, it's recommended to apply the coating on the inside of the crystal, which can help maintain the best AR performance. It's essential to keep in mind that if the sapphire crystal is scratched, polishing it won't be practical, and it will need to be replaced instead.

Providing a watertight seal

In the manufacturing process of watches, it is common to use mineral or sapphire crystals for the watch cases. These crystals are typically paired with hard materials like steel or titanium to ensure durability and longevity. However, since these materials lack flexibility, a gasket made of nylon is required to create a waterproof seal. The nylon gaskets come in a variety of shapes, including flat, "I" or "L" shapes. These shapes are designed to fit snugly between the crystal and the case rim to create a tight and secure seal. To insert the crystal into the case, a specialized crystal press tool is used. This tool applies pressure to the crystal, which in turn squeezes the gasket into place.

Sapphire Shine - The TSAR BOMBA Watch

Introducing the "TSAR BOMBA" MIYOTA JS20 Sapphire Mens Watch TB8801Q - a perfect blend of strength and elegance. This watch features sturdy sapphire glass that provides unparalleled scratch resistance, ensuring clarity and longevity, and an elegant octagonal bezel design that is crafted from scratch and corrosion-resistant stainless steel. Its imported Japanese rubber strap adds both comfort and style, while its impressive 100m water resistance makes it a fitting choice for any occasion. Furthermore, its presentation in an elegant box makes it an exemplary gift for special occasions. 


The TSAR BOMBA watch promises to deliver an exceptional experience and appearance, attesting to its dedication to quality and craftsmanship. Experience the unique combination of raw power and exquisite craftsmanship on your wrist with this exceptional timepiece.


Considering all this, using sapphire glass as a material for watch faces has many benefits. Pure aluminum oxide is precisely synthesized in sapphire glass, resulting in unparalleled clarity that allows light to pass through with minimal distortion. Sapphire glass is also exceptionally resilient and scratch-resistant, making it superior to other materials like mineral and acrylic glass. 

Additionally, when combined with an anti-reflective coating, sapphire glass further enhances the appearance and quality of a watch by reducing reflections and glare. If you're looking for a timepiece that is both durable and elegant, the "TSAR BOMBA" watch with sapphire glass is an excellent choice that exudes both strength and sophistication.

16 août, 2023 — WBO Solutions