It is said that the first Rolex equipped with sapphire crystal was the Oyster Quartz created in 1970. Till 1980s, the robust sapphire crystal had been widely used on the hot perfect fake Rolex watches. It is easy to distinguish the acrylic glass from sapphire by tapping it with the fingertips.
The sapphire crystal is extremely robust. Only the diamond is harder than the sapphire crystal. But it is easy to be broken. From the pictures, you will find that the sapphire crystal is much clearer than acrylic glass and it is also much more beautiful.
From the thickness of these two material, you will clearly find that the acrylic glass is much thicker than sapphire crystal. The Oyster Perpetual launched in 1991 might be the world’s last Rolex with acrylic glass. From then on, the modern top quality copy watches of Rolex are all equipped with the robust sapphire crystal. While for people who are interested in vintage timepieces with domed glass, the acrylic models are irreplaceable.