Luxury Fashion Accessories: Different Types of Watch Crystal Dial Windows Explained

Thursday, 12 August 2021

Different Types of Watch Crystal Dial Windows Explained

What is a Watch Crystal?

Also referred to as a dial window, a watch crystal is the transparent (see-through) covering that protects the watch face or dial.

N.B. Not to be confused with the crystal that acts as an oscillator in a quartz watch, typically referred to as “quartz crystal”!

Different Types of Watch Crystal

There are 3 main different types of watch crystal that is commonly used to protect the watch face or dial:

· Acrylic crystal / plastic

· Mineral crystal / glass

· Sapphire (synthetic) crystal

Let’s take a look at each of these types of crystal dial windows in more detail to help you understand the differences between them:

Acrylic crystal / plastic

Acrylic crystal is the cheapest of all the watch crystals and is made from transparent plastic (sometimes also referred to as Plexiglass).

Acrylic crystal is less scratch-resistant than all the other types of crystal and also reflects more light. However, minor scratches in acrylic crystal are easier to buff out than with other types of crystal. Acrylic crystal/plastic is lightweight and shouldn’t shatter or crack like glass so is ideal for sports or children’s watches.

Acrylic crystal is used less often than it used to be and is more likely to be found in cheaper watches.

Mineral crystal / glass

Mineral crystal is made from glass that has been heat or chemically treated to make it more scratch-resistant.

Mineral crystal is more scratch-resistant than acrylic crystal and although hard-wearing, mineral crystal is not crack-proof or shatter-proof like plastic.

Many mineral crystal dial windows have been treated to make them anti-reflective and glare-resistant.

Mineral crystal is not as durable as sapphire crystal but is less expensive to make and is a popular choice of crystal in a wide range of watches.

Some manufacturers have added processes to their mineral crystal to toughen it and make it even more durable and resistant to scratches and knocks, e.g. Hardlex glass by Seiko, Pulsar & Lorus.

Sapphire (synthetic) crystal

Sapphire crystal dial windows are not actually made from real sapphire, but are synthetically produced to make a compound similar in properties to its real counterpart.

Sapphire crystal is the most expensive of the 3 main crystals to produce and is the most durable of them all.

Sapphire crystal is 3 times tougher than mineral glass, much more scratch resistant and less likely to break.

Sapphire crystal is typically used by the more expensive watch brands such as Omega or Gucci and is also used by some of the cheaper watch brands in their top-of-the-range watches.

Some watch manufacturers use a combination of mineral and sapphire crystal together such as Seiko’s Sapphlex which consists of Hardlex mineral glass covered with a layer of synthetic sapphire crystal (typically used in sports watches).