YouTuber Zack Nelson (JerryRigEverything) decided to compare the durability of the lenses that protect the Samsung Galaxy Watch 5, Apple Watch Ultra and Garmin Fenix 7 Sapphire Solar smartwatches. Manufacturers of all three devices claim to use “ultra-durable sapphire glass.”
Nelson noted that ordinary tempered glass is scratched by an object with a hardness of 6 or higher on the Mohs scale, whereas sapphire glass can be scratched at level 8 or even 9 (depending on how pure it is).
Confirmed to use sapphire glass
Using a gem detector that evaluates the thermal conductivity of the materials, the famous YouTuber found that all three models actually use a sapphire crystal coating. However, the damage test of each smartwatch revealed different results:
- Samsung Galaxy Watch 5: almost imperceptible scratches at levels 6 and 7 on the Mohs scale, severe scratches at level 8
- Garmin Fenix 7 Sapphire Solar: Serious scratches at level 8
- Apple Watch Ultra: Visible scratches at levels 6 and 7, severe scratches at level 8.
JerryRigEverything believes the Apple Watch Ultra’s relatively poor protection against glass damage is due to impurities or polishing issues in the sapphire.