One way they can form is through rapid cooling which means they don’t develop in the repeated units that define true crystals, but it's up for debate if you can technically have an "amorphous ...

Shown above are representative snapshots of the compression of hexagonal ice to high-density amorphous ice. Blue and red spheres represent different local environments of water molecules based on ...

The phase change from crystalline to amorphous is achieved by highly localised application of laser pulses, which consumes a lot of electricity. The crystals must be heated beyond 800 degrees C ...