Should You Get Sapphire Crystal or Mineral Crystal?

seiko modification parts

For a watch’s dial, its “crystal or glass,” or its transparent protective covering, may be the most susceptible to wear and tear. The crystal usually comes in different shapes and sizes. There are various crystals based on the watch and the manufacturer, each designed to provide protection from natural elements and prevent breakage. 

For example, sapphire crystal is very hard and scratch-resistant and is often used in waterproof watches. In contrast, mineral crystal is more scratch-resistant than quartz crystals but not as scratch resistant as sapphire. Acrylic hesalite and plexiglass are cheaper materials that denote low quality in fine watches, primarily if used in dive watches.

When choosing the best crystal material for a watch, consider not only the material of the crystal but also its cost. Depending on the crystal used, watches can have different values and prices.

Today, we will look at two popular crystals, sapphire crystal and mineral crystal. Which should you get?

Sapphire Crystal

In the watch industry, sapphire crystal is a general term that describes a harder transparent substance than quartz crystals or other synthetic material. It is a naturally occurring form of oxide. It is the second hardest naturally occurring material behind the diamond.

Due to this, hardness is resistant to scratches, wear and tear and is also exceptionally hard to break. High-end watches are made with this material as a protective covering because of their durability and low cost compared to other materials, such as gold.

Mineral Crystal

Mineral crystal is one of the most common types of crystals in watches. It is a transparent, synthetic substance that is harder than glass and other synthetic materials.

Mineral crystals are made of metal oxides. These include iron(III) oxide (FeO), iron(II) oxide (FeO), and aluminium oxide (AlO) with a slight amount of water (HO) and polymer binders. This makes it softer than sapphire. To keep the material in a solid-state and prevent it from becoming a liquid, a small amount of glycol (a type of alcohol) is added.

Mineral crystal is the least expensive type of crystal used in watches, and it is known for being the most scratch-resistant material available. Although it is not as scratch resistant as sapphire, mineral crystal is still considered one of the best crystal materials for watches.

For Seiko Mods, Which is Better?

When choosing a watch crystal, there is no one-size-fits-all solution. It depends on the customer’s needs, and high-quality watches will use both types. Seiko is a well-known watch manufacturer that publishes watch manuals for its customers. They’ve even created manuals that list the use of sapphire and mineral crystal for their dive watches.

In general, there is not a big difference in scratch resistance between sapphire and mineral crystals. However, sapphire crystal is considered to be more scratch-resistant than mineral crystal.

This is because sapphire crystal’s hardness makes it more resistant to scratches than mineral crystals and because sapphire crystal can be polished very thinly and more easily. For this reason, it is often used in high-quality watches that have a sapphire crystal.


Although sapphire crystal is more scratch-resistant than mineral crystal, mineral crystal is the most economical and the most scratch resistant. If you are looking for a high-end watch and are willing to pay the price for it, then the sapphire crystal is the best choice for you. But if you are looking for an economical watch, then the mineral crystal is the way to go. In the end, your choice should be based on your watch collection and your budget.

If you are in the market for Seiko watch parts, we can help you. Seiko Mods specialises in designing and manufacturing Sapphire Crystals and custom parts for Seiko watches. We can provide you with precisely what you need. Just contact us to get started!

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