Sapphire crystal and mineral glass are two of the most commonly used materials for watch faces.  While both materials have their own benefits, it is important to understand the differences between the two so you can make an informed decision when purchasing a watch.  In this blog post, we will explore the properties and benefits of sapphire crystal and mineral glass, and compare their differences in terms of durability, scratch resistance, clarity, and cost,how to distinguish sapphire glass from mineral glass, etc.

Table of Contents

What is Sapphire crystal?

  Sapphire crystal is an artificially created material that is produced by crystallizing pure aluminum oxide at extremely high temperatures. Its physical properties are similar to those of natural sapphires, including exceptional hardness that is second only to diamonds on the Mohs hardness scale. The synthetic sapphire shares the same level of hardness as natural sapphires, making it highly resistant to scratches and damage.

what is Sapphire crystal
what is mineral glass

What is Mineral glass?

 Mineral glass is a material made from glass. Now almost all mineral glass watches are tempered mineral glass. The raw materials of mineral glass are mainly silica and sodium carbonate. 

Mineral glass is also known for its clarity and transparency, making it an ideal choice for watches..

Differences Between Sapphire Crystal and Mineral Glass

Scratch resistance

Sapphire Crystal has a hardness of 9, making it the hardest of all watch glass materials.  It usually requires a diamond or similar substance to scratch it.  In comparison, Mineral Glass has a hardness between 5 and 7, making it more prone to scratches. 


Sapphire Crystal has higher transparency than other watch glass materials due to its high crystalline quality, and it doesn’t become hazy over time and under environmental stress.  Mineral Glass has a relatively high transparency, but it’s slightly inferior to Sapphire Crystal.


Due to its high cost and relatively fragile nature, Sapphire Crystal is usually limited to high-end watches.  If the watch is subjected to impact or shock, it may cause the glass to shatter or crack,which is also a disadvantage of sapphire glass. In comparison, Mineral Glass is relatively durable, but its impact resistance is relatively poor.


Sapphire Crystal is typically more expensive than Mineral Glass and is a high-end watch glass material.  In contrast, Mineral Glass is commonly used in low- to mid-range watches and has a lower cost. The cost difference between Sapphire crystal and mineral glass is significant. Generally, Sapphire crystal surface glass of the same size and thickness can cost 5 times or more than mineral glass.

It’s important to note that the performance of watch glass materials is not only determined by the material itself but also influenced by its manufacturing process and application.

How To Tell Sapphire crystal From Mineral glass

Water drop

 By the way, you can easily check whether your favorite watch comes with sapphire glass using the so-called water drop method: dab a drop of water on the surface of the watch glass and observe its behavior.  If the drop remains spherical, it is sapphire crystal.  If it spreads and flows, it is mineral glass..

How to tell mineral glass from sapphire crystal
The difference of Sapphire crystal and mineral glass

 The glass color

Crystal Sapphire and mineral glass can be distinguished by the color of the side of the glass. If the color is milky white, it’s sapphire crystal glass. If it’s blue, it’s mineral glass.

Use a tool near you, similar to a knife to scratch the glass

If the knife scratch the glass, it’s mineral glass. If glass can’t be scratched, it’s crystal sapphire glass.

. Touch and feel

If you touch sapphire, you will feel cold, it is not mineral.

Mineral glass VS sapphire crystal?Hard to decide,Sapphire coated mineral glass is also a good solution.

Sapphire coated mineral glass refers to a type of glass surface that is made of mineral glass but has been coated with a layer of sapphire crystal for increased scratch resistance and durability.

This innovative material boasts improved impact resistance compared to traditional mineral glass, while its sapphire coating ensures that only a diamond can scratch its surface. As a result, the combination of mineral crystal glass with a thin sapphire layer provides a substantial increase in both impact resistance and scratch resistance, making sapphire coated mineral glass a compelling option for various applications.


      In summary, sapphire crystal and mineral glass both have their own benefits and drawbacks. Sapphire crystals withstand scratches very well and can only be scratched with certain rare materials, mainly diamonds, especially hard rock types.  Mineral glass, which is commonly used to make watch glasses, is easier to scratch but better able to withstand impact.  While sapphire crystal is more durable, scratch-resistant, and transparent, mineral glass is more affordable and still offers a high level of durability and scratch resistance.  When choosing between the two, it is important to consider your budget, intended use, and aesthetic preferences

Related products-Sapphire crystal watch

Sapphire crystal watches are highly recommended for anyone looking for a timepiece with exceptional durability and scratch resistance. Sapphire crystal is second only to diamonds in terms of hardness, making it an ideal material for watch faces that are exposed to daily wear and tear. In addition to its toughness, sapphire crystal is also highly transparent and clear, providing a crystal-clear view of the watch’s hands and dial. a sapphire crystal watch is an excellent choice. So why not treat yourself to the unparalleled beauty and durability of a sapphire crystal watch today?

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